Anorectal Malformations with Dr. Andrea Bischoff

Pediatric Surgery
Discussion with Dr Andrea Bischoff and Dr Todd Ponsky regarding anorectal malformations.


  • Evaluation of the male baby with an anorectal malformation (01:19)
  • Distinguishing a normal anus from a perineal fistula (03:08)
  • Associated anomalies (04:39)
  • Timing of surgical repair (10:19)
  • Evaluation of the female baby with an anorectal malformation (12:45)
  • Evaluation of the older child with an anorectal malformation (13:57)
  • Evaluation of the male baby with a high anorectal malformation (16:08)
  • What is the ideal colostomy? (17:38)
  • Distal colostogram (19:31)
  • Choice of procedure for different anorectal malformations (22:19)
  • Evaluation of cloacal anomaly (24:30)
  • Prognosis after repair of anorectal malformations (27:28)
  • Enema technique (32:45)
  • Bowel management for incontinence (35:58)
  • Malone stoma (39:48)
  • Bowel management for constipation (41:33)

Additional Content

Evaluation of the male baby with possible anorectal malformation (01:19)


Dr. Ponsky: Let’s get into it Andrea. I want to give you a case and tell me how you’d handle this. You’re called to the neonatal intensive care unit because there’s a male baby that was born, and they either can’t see the anus or they believe that the anus is just too small, maybe they’re saying that it’s anteriorly located. How do you manage that patient?

Dr. Bischoff: Your first mission is to go to the neonatal intensive care unit and carefully examine the perineum to determine if the patient indeed has an anorectal malformation or not. Patients with anorectal malformations with good prognosis for bowel control will have well-formed buttocks with a good midline groove and a good anal dimple. Patients with malformations with a bad prognosis for bowel control will have a flat bottom and an unclear delineation of the anal dimple. If we are dealing with a male patient, it is very important to remember that there are different manifestations of rectal perineal fistula. In some cases the hole is extremely small, and if you don’t suspect and carefully look for it, it can be missed. Concerning the size to determine if it is a small anus or if it is a normal caliber anus, it is important to remember that in a newborn baby one should be able to accommodate a #12 Hegar dilator. That would be a normal anus. Once you determine that the baby has an anorectal malformation or rectal perineal fistula then you should concentrate on ruling out important associated defects during the first 24 hours before even thinking about taking the patient to the OR.

Distinguishing a normal anus from a perineal fistula (03:08)

Dr. Ponsky: How do you determine that an anus is anterior besides the dimple? Is there a measurement trick you use?

Dr. Bischoff: We don’t even say anterior because we don’t like the term anterior anus because it goes with the definition of an anus. An anus has to have a normal caliber like what I just mentioned, a #12 Hegar dilator, but it should also be surrounded completely by sphincter mechanism, and that’s not what we see in a perineal fistula. In a perineal fistula we see a small caliber and it is not completely surrounded by sphincter. Just by looking at the discoloration of the skin, you can see the sphincter mechanism of the rectal perineal fistula is in a horseshoe shape so the posterior and lateral portion have sphincter but the anterior does not have sphincter.

Dr. Ponsky: Okay. You’re looking at, and I’m glad you’re correcting me that it’s not an anterior ectopic anus -- it is actually a perineal fistula, and you look at really how it looks on the outside. I was once taught to measure the distance between the tip of the coccyx and the bottom of the scrotum is that not a good measurement trick?

Dr. Bischoff: It is unnecessary.


Associated anomalies (04:39)


Dr. Ponsky: That is very enlightening for me. Andrea, so you go to see this child, and you are concerned that there’s a perineal fistula. What other malformations do you have to rule out and look for and then what sort of studies would you order?

Dr. Bischoff: On all anorectal malformations you have to rule out the associated common anomalies so esophageal atresia would be one that can be ruled out by trying to place a nasogastric tube, remembering that 8% of patients with anorectal malformations will have esophageal atresia. It is also important to rule out cardiac anomalies and you can do that with an echocardiogram if it is available or with a good physical examination looking for murmurs. Thirty percent of the patients with anorectal malformations will have cardiac anomalies but in only 10% of them is the anomaly hemodynamically significant. A babygram, which is a radiograph of the entire body looking for abnormalities of the spine like hemivertebrae, extra ribs, double bubble sign representing a duodenal atresia, and kidney ultrasound to rule out hydronephrosis. Fifty percent of patients with anorectal malformations have associated urological defects. A spinal ultrasound to rule out tethered cord since 25% of patients have tethered cord. Last but not least a radiograph of the sacrum anterior-posterior and lateral which allows you to rule out hemisacrum that is associated with a presacral mass. Also, you want to calculate the sacral ratio, which correlates with future functional prognosis of bowel control. If during the first examination one could not identify the fistula, the patient should be reexamined after 24 hours. It takes time for the air to travel distally to the rectum to become distended to increase the intraluminal pressure overcoming the muscle tone of the surrounding sphincter mechanism. It also requires a significant pressure for the meconium to pass through a tiny perineal or urethral fistula. If no meconium is seen in the perineum then you can order a cross table lateral film with the pelvis elevated to try to identify the distal air representing the rectum. This study should never be done before 24 hours of life, because it will give the false impression of a high malformation due to the muscle tone that I just mentioned.

Dr. Ponsky: I want to ask a question. You did say you could get an echo or a good physical exam. If you hear no murmurs are you satisfied with that?

Dr. Bischoff: If it is a newborn and I’m here at Cincinnati Children’s, and I’m thinking about putting the patient under anesthesia, I order an echocardiogram. If I’m in a place where I don’t have one available, and a patient is completely stable and the physical exam is completely normal, I think you are safe to put him under anesthesia without an echocardiogram.

Dr. Ponsky: Okay, that’s a good point. The other question is you mentioned a spinal ultrasound to rule out tethered cord. At what age do you have to start getting an MRI?

Dr. Bischoff: Three months. If the baby is less than 3 months, it is good enough to see with a spinal ultrasound. After that, because of the ossification process, you need an MRI to correctly see the tethered cord.

Dr. Ponsky: Let’s say there’s a tethered cord. How do you time that out with the repair? What do you do first?

Dr. Bischoff: That’s a very controversial subject. Once we detect a tethered cord our general guideline for the parents is that from our observation tethered cord has more influence in the urinary tract rather than in the gastrointestinal tract meaning in terms of prognosis tethered cord usually affects the urinary tract more. We would not delay our repair based on tethered cord. Normally, we repair the malformation and then the neurosurgeon sees the patient. If there’s a large myelomeningocele defect then it’s a different scenario.

Dr. Ponsky: Okay. What if you find a hemisacrum?

Dr. Bischoff: If you find a hemisacrum you are obligated to rule out a presacral mass and in this case an MRI would be indicated to see the presacral mass and also to determine its relationship with the spinal canal and better prepare you for surgery. At the time of the rectal repair, the presacral mass should also be addressed and removed. The significance of finding a presacral mass is that it usually changes the prognosis for bowel and urinary control, remembering that those presacral masses are most commonly found in malformations with good prognosis such as rectoperineal fistula, rectovestibular fistula, and rectal atresia, but when the presacral mass is present then the prognosis changes.


Timing of surgical repair (10:20)


Dr. Ponsky: So now 24 hours have passed and you’ve got the results of the tests and you’ve found that there are no abnormalities. What do you do with the patient after 24 hours?

Dr. Bischoff: It comes the moment to decide between primary repair, which can be done immediately or electively, or a colostomy with a delayed repair. To decide which way to go, you should take into consideration many factors including the surgeon’s experience with newborn repair, the condition of the patient, and the local circumstances surrounding the patient and the surgeon. For example, if we are dealing with a baby that is too small, a preemie, that has a cardiac problem and a rectal perineal fistula, then there is no urgency in repairing the anorectal malformation. If the patient is stooling satisfactorily then you can wait until the patient is stable enough to tolerate the operation. If the patient is having some trouble passing stool, a gentle dilation can be done just to allow for the stool to be evacuated. In this case, you are not truly dilating the patient; you just want the stool to be evacuated without difficulties, so a #6, 7, or 8 Hegar is more than enough for that goal to be achieved. If the surgeon is experienced with newborn repair and you have a good anesthesiologist with experience dealing with newborns, then a primary repair could be done. The advantage of a primary newborn repair is that a bowel preparation is not required since the meconium is considered sterile. The last scenario is a surgeon that does not have experience with primary repair and decides to do a colostomy. There is nothing wrong in doing a colostomy, and it is for sure the safest way to approach an anorectal malformation. It is better to open a colostomy and have a perfect operation than to do a primary repair and have a complication such as the dehiscence or retraction that requires a reoperation. We like to say that patients with an anorectal malformation have one chance to have the right operation. Secondary operations or reoperations usually change the prognosis for bowel control in these patients.


Evaluation of the female baby (12:46)


Dr. Ponsky: Okay, Andrea. I know I’m going to have a question later about the specifics of a colostomy, but let’s take a different track. Let’s say the baby is born and is a female, then what would be different in what you’ve already told us about these patients?

Dr. Bischoff: In a female, it is important to pull the labia back in order to clearly see the urethra and vagina as two separate orifices. It is important to make sure that the patient actually has a vagina, as you don’t want that to be a surprise in the operating room. If you think that there is a vestibular fistula present it will be exactly in the midline immediately posterior the vagina. You should try to use an 8-French feeding tube to catheterize the fistula if you cannot see it. Remember that vestibular fistula is the most common type of anomaly. If you are examining a patient, a female patient, and you cannot see the fistula, try to probe it with an 8-French feeding tube as most likely you will be able to find a rectal vestibular fistula.


Older child with an anorectal malformation (13:58)


Dr. Ponsky: Let’s go to a different scenario now, Andrea. So a baby is born and nobody noticed there was anything wrong with the anus but you receive a call from the pediatrician asking you to give a second opinion about the child that has a rectoperineal or vestibular fistula but is growing, eating, and pooping, but suffers from constipation. This is a baby that wasn’t detected immediately but later it was detected and he’s doing okay: growing, eating, pooping but is having some constipation. How do you manage that?

Dr. Bischoff: Unfortunately, in our dream world we would dream that this would never happen, but that all patients would have their diagnosis correct at birth. The reason is that the scenario you just gave me that the patient is doing well is great, but we have seen patients that were not diagnosed and they almost perforate and die from this missed diagnosis, so in the scenario that you gave me there is no rush. I would see that patient in clinic, examine the perineum, confirm the diagnosis of anorectal malformation, and explain to the parents what it is and how the operation is going to be. While we are looking to electively book the case, I would order studies to rule out associated anomalies. In this case some of them would not have to be ruled out since they have already been ruled out so we get a sacral x-ray, kidney ultrasound, spinal ultrasound if the baby is less than 3 months in age or spinal MRI if the baby is more than 3 months in age. In this case, because the baby is already home and eating, we would need a complete bowel preparation prior to surgery.

Dr. Ponsky: What kind of bowel prep do you do?

Dr. Bischoff: We do GoLYTELY, so we admit the patient the day before with a nasogastric tube and we run 25 ml/kg/hr in cycles of 4 hours until the patient is completely clean.


Evaluation of the male baby with a suspected high anorectal malformation (16:09)


Dr. Ponsky: Great, let’s go back to what we were talking about before. Now the baby is in the NICU, and you examine the perineum and you cannot identify a rectoperineal fistula; you see nothing there. Twenty-four hours go by. You go back, and there’s no sign of meconium still in the perineum. There is actually an impression that there is a meconium mixed with the urine by the nurses and yourself. What do you do in this situation, since there looks like there might be a fistula?

Dr. Bischoff: We’re talking again about a male newborn, and the anus was not identified, so the screening of associated defects should be the same as we just described in the first scenario. Now we are dealing with a male patient, possibly with a rectourethral bulbar fistula, rectourethral prostatic fistula, or recto-bladder neck fistula. We would only know for sure the type of malformation that were dealing with after we open a colostomy and do what we consider the most important study for a male patient: the high pressure distal colostogram. The opening of a colostomy is an operation frequently underestimated by many surgeons, but it should be taken as seriously as the main repair since a wrong colostomy opening might have serious future consequences.


What is the ideal colostomy? (17:38)


Dr. Ponsky: This is actually something that I learned when I went to Dr. Peña’scourse when I was a resident, and I still remember it and use it to this day. Can you go through and explain to us what would be an ideal colostomy?

Dr. Bischoff: Okay. The ideal colostomy should be a totally diverting one since in the majority of cases we want to avoid contamination of the urinary tract with stool. It should be located in the descending colon to leave enough distal bowel for the pull-through and to avoid prolapse of the proximal stoma since the descending colon is fixed to the abdominal wall. The location of the proximal stoma in the abdomen should be in the center of a triangle formed by the left rib, the umbilicus, and the iliac crest to be sure that the stoma is surrounded by normal skin to apply the stoma bag. The distance between the two stomas, the proximal and the distal, should be enough to allow for the stoma bag to cover only the proximal stoma. The distal stoma, or the mucus fistula, should be made small to also avoid prolapse. During the colostomy creation, the entire distal bowel should be irrigated with plenty of normal saline to remove all the meconium. If you follow those steps, you will have the perfect colostomy.


Distal colostogram (19:31)


Dr. Ponsky: Okay, that’s a great trick. I think that, from what I’ve seen in some of you and Alberto’s presentations, some people have definitely made stomas that led to difficulty in the future, so this is a really important thing to keep in mind. Then, I’m assuming you’re going to get your distal colostogram. How do you do that?

Dr. Bischoff: The technique for the distal colostogram is actually pretty simple. The patient has to be in the fluoroscopy suite. We insert a Foley catheter into the mucus fistula and the size of the Foley catheter will depend on the size of the mucus fistula. Just to give you an idea, since we make a tiny mucus fistula, we normally use an 8 French Foley catheter.  We inflate the balloon of the folly and pull it back so it can act as a plug to avoid leakage of the contrast. The patient should be supine. The contrast material should be hydrosoluble and you have to place a radiopaque anal marker at the anal impression. As I just mentioned, the initial images are taken with the patient lying supine on the table. You start injecting contrast and you see the colon being filled with the contrast material. It’s important to have this AP view so you can see how redundant the colon is as that will help you to decide if you have enough bowel available for the pull-through. Once the contrast fills the entire distal bowel, you should turn the patient in perfect lateral position with the knees making a 90-degree angle and one femur exactly in front of the other femur. At this position, you want to make sure that the radiologist shows all your points of reference that are the mucus fistula side where the Foley balloon will be, the sacrum, and the anal marker. Most radiologists are obsessed about making the field smaller and sometimes they cut the sacrum, and you, as a surgeon, need to see everything. You keep injecting contrast until you overcome the muscle tone and you identify the fistula side. The contrast will normally fill the bladder, and you keep injecting until the patient voids. Then you have the image that you need showing the fistula, showing the amount of bowel that you have for the pull-through, showing the bladder filled and the relationship with the urethra. That’s what you need. You should never approach a patient without having this study done correctly.

Dr. Ponsky: Okay. That was a great review, and I’m hoping we can get this in the hands of the radiologists as well so they can review what you just said because I think that it’s important. This is a broad question, but I think that this is something that I would like clarification on.


Choice of procedure for different anorectal malformations (22:19)


Dr. Ponsky: Can you go through the different types of malformations and what the operation would be based on the different malformations?

Dr. Bischoff: Sure. Let’s suppose that the distal colostogram showed a rectourethral bulbar fistula. First of all, in all male patients, you must have a Foley catheter in place for the surgical repair. So in a rectourethral bulbar fistula the rectum will be reachable posterior sagittally, and the most important portion of the operation will be the separation between the rectum and the long colon wall with the urethra. The mobilization of the rectum will be minimal because it’s already very low in the pelvis. In a rectourethral prostatic fistula you can also repair it posterior sagittally. The colon wall with the urethra is shorter compared to the rectourethral bulbar fistula, but you will need more rectal dissection in order to gain length for the rectum to reach the perineum without tension. Depending on the case, this type of anomaly can be repaired laparoscopically when the surgeon has experience with that and when you’re dealing with a high rectoprostatic fistula. In cases of recto-bladder neck fistula, you need laparoscopy or laparotomy. The good thing is that the rectum joins the urinary tract in a "T” fashion. The ligation of the fistula is actually the easy portion. The challenge in this case is how to gain enough length to reach the perineum and preserve good blood supply to the rectum. The way to achieve that is by selectively ligating mesenteric vessels but preserving a good blood supply.

Dr. Ponsky: That selective ligation of the mesenteric vessels can sometimes be a little nerve-wracking hoping you doesn’t cause ischemia to the bowel.


Evaluation of cloacal anomaly (24:30) 


Dr. Ponsky: Let’s go back to the NICU. What if we have a female patient with a single perineal orifice? How do you approach this? What does this mean?

Dr. Bischoff: Just with your description you made the diagnosis of a cloaca. A diagnosis of a cloaca is a clinical one. In most patients a single orifice will be located at the normal urethral site. In some patients it is located at the tip of a prominent pseudo-phallus and if I can make a plea to pediatric surgeons, I would ask them to disagree strongly when the neonatologist labels a cloaca patient as a disorder of sexual differentiation, in the past also known as ambiguous genitalia or intersex. As you can imagine this is a significant unnecessary burden to the family. If the patient has a single orifice, you palpate the pseudo-phallus and it is skin and there’s no corpora. This is a cloaca and we’ve never seen cloaca with a disorder of sexual differentiation. They are all females with normal ovaries. But, unfortunately, we have seen many patients who have received this diagnosis and were even started on steroids due to this erroneous diagnosis. So let’s go back to the cloaca diagnosis. What is special in the newborn screening is to add a pelvic ultrasound to rule out hydrocolpos, a very dilated vagina filled with fluid. When you ask the radiologist for an ultrasound, you have to tell him to look for a cystic mass behind the bladder. If a hydrocolpos is present, it should be permanently drained with a transabdominal indwelling tube until the main repair. The colostomy recommended is the same one that I just described, and, at the time of the colostomy creation, the hydrocolpos should be drained. Prior to the repair, it is important to have besides the distal colostogram, a determination about the length of the common channel. We can do it either in fluoroscopy; we have here a 3D cloacal gram and inject contrast in all the cavities, or you can just use a cystoscope to measure. If it is a cloaca with a common channel length less than 3 cm, it can be repaired posterior sagittally with a total urogenital mobilization. Cloacas with more than 3-cm common channels require a surgical decision-making algorithm which is a little more complicated to discuss without images, and I think this should be referred to surgeons with experience in dealing with this complex malformation.

Dr. Ponsky: Yeah, that’s a key point to make is to know when to refer for these complex patients.


Prognosis after repair for anorectal malformations (27:28)


Dr. Ponsky: Can we predict the future a little bit and discuss what is expected for each patient based on the type of anorectal malformation?

Dr. Bischoff: Thank you so much for asking this question. I think this is a very important subject, Todd. We actually believe that parents should have this information about how the future is going to be in terms of prognosis for bowel control as early as possible in life to correctly adjust their expectations. So thanks to Dr. Peña’s large database we can now tell early in life what is the future prognosis for bowel control based on the type of anorectal malformation. For example, in a rectal perineal fistula, provided they have a normal sacrum and normal tethered cord, they have a 100% chance of bowel control. But in all malformations, the ones with better prognosis for bowel control are the ones that will suffer from more constipation. For rectoperineal fistula expect that they will have severe constipation, and this constipation should be managed early in life with the correct amount of laxatives. Rectovestibular fistula, provided again that they have a normal sacrum and no tethered cord, they have a 95% chance of bowel control. Again, they will suffer from severe constipation and should be managed early in life with laxatives. Rectourethral bulbar fistula has an 85% chance of bowel control. Anorectal malformations without fistula have an 80% chance of bowel control. Rectourethral-prostatic fistula has a 60% chance of bowel control. Recto-bladder neck fistula has 20% percent chance of bowel control, so this is not a good malformation in terms of future prognosis. For cloaca, it’s a little harder to characterize them. If it’s common channel less than 3 centimeters, they have normal sacrum, and no tethered cord, we would say, generally speaking, about 70 percent chance of bowel control.

Dr. Ponsky: Then, in a patient, for example, that you think has a high chance of lack of bowel control, let’s say maybe the recto-bladder neck fistula patients, is it indicated then at that point that you should just keep the colostomy?

Dr. Bischoff: We think that the only indication to keep a colostomy would be the incapacity to form solid stool. Most patients with anorectal malformation will have a normal colon, they will be able to form solid stool, and they will respond to our bowel management program and then be clean in the underwear. Formally, we don’t consider patients with anorectal malformation, even when the prognosis is poor for bowel control, an indication for permanent colostomy, because we have seen that patients prefer the quality of life of a pull-through with bowel management rather than with a colostomy. We believe that all children with anorectal malformations should be out of diapers at the same age that other children are normally out of diapers; here in the United States, it’s usually at 2 years of age. Before 2 years of age, the parents and the surgeon should just avoid the constipation because all the children will be in diapers it makes no difference, and try to establish regularity as much as possible in terms of meals and bowel movements. If after 2 years of age the child has not potty-trained, we recommend to start the formal bowel management program with enemas for children with bad prognosis for bowel control, with enemas on temporary basis for children with border-line bowel control, and then every year we can try to test if they can be stopped on the enemas, and with laxatives for children with bowel control and constipation. The bowel management for children with bad prognosis for bowel control consists on finding the enemas that completely cleans the column and allows for the child to be clean of stool in the underwear for 24 hours. It is an artificial way to keep them clean in the underwear, so we consider, again, that the only indication for a permanent colostomy is incapacity to form solid stool, and that would be extremely rare in a patient with anorectal malformation. Now, I know Dr. Peñawill be discussing cloacal extrophy, and then he will go into the details about patients that have short colon or absent colon.

Dr. Ponsky: Yeah, and I think that’s going to be a great discussion and that’s a nice little teaser so that the listening audience knows, to keep you in suspense. There will be a great discussion on cloacal extrophy with Dr. Peña coming soon.

Enema technique (32:45)


Dr. Ponsky: Andrea, what is the magic recipe for the enema?

Dr. Bischoff: Unfortunately, there is not a magic formula or recipe. Determining which enema works for each child is a trial-and-error process and it takes usually about one week to find out the precise enema for each child. I can give you some general guidelines on how we do it. The first step is to get a contrast enema with hydrosoluble material without bowel preparation. With the image, we can divide patients who are fecally incontinent into two groups: those with a dilated colon and tendency for constipation and those with a non-dilated colon and tendency for diarrhea. For the first group, dilated hypomotile colon, they need a large and concentrated enema to clean the colon. But the good thing is that after the enema, provided we clean the colon properly, we do not have to worry about it because the colon will have the natural tendency not to produce a bowel movement. Now for the second group, the non-dilated hypermotile colon, we need a small enema. Cleaning the colon is very easy, sometimes with normal saline without irritants to clean it, but the challenge is how are we going to keep this colon from moving in between enemas? Usually with these patients we need to add a constipating diet with three meals per day and medication to slow down the colon.

Dr. Ponsky: What I just heard you say is normal saline, is that it? Just normal saline or do you use soapsuds or other things?

Dr. Bischoff: Normal saline is the base of the enema, and we usually use between 200-1,000 mL. Now, in order to increase the concentration, to make it more of an irritant, we add liquid glycerin between 10-40 mL. We can also add castile soap; that’s a mild hand soap that is also glycerin-based, and each package has 9 mL so we use between 9-27 mL. Also, Fleet enema, sodium phosphate, which we use according to the patient’s age. So, if the patient is between 2-4 years of age we only use 33 mL of Fleet, that’s half of a pediatric Fleet. If the patient is between 7-10 years of age, we use a pediatric fleet that’s 66 mL. If the patient is more than 10 years of age, then we can use an adult fleet that is 133 mL.

Dr. Ponsky: Okay, so you don’t usually give someone just saline. You add the glycerin, or the soap, or you do Fleets—is that right?

Dr. Bischoff: For the patients that have a distended colon we always use saline plus additives. So, glycerin, soap, or fleet. For patients who have a non-dilated, hypermotile colon, we start just with normal saline.


Bowel management for incontinence (35:58)


Dr. Ponsky: Okay. We have started a bowel management program here at Akron Children’s now that Aaron Garrison is here and we have been very much asking your advice as this process has been developing before Aaron got here, even, on how do we start the bowel management program. I know, in fact, our nurse, Shelly, actually went down and spent a lot of time in your clinic to try to better understand how to start a bowel management program. What’s the most common question you get from people starting these programs?

Dr. Bischoff: Besides the logistics, one great piece of advice is to come spend a week with us. Every month we have a bowel management week so if you’re thinking about starting a program a good idea is to come here with your own nurse and spend the week with us. But, in terms of the question that we get most often and what’s the difficult portion, I feel that most pediatric surgeons, in the beginning, have difficulty guessing what’s going to be the first enema. And I always say don’t be afraid because you have the entire week to find out; if you select one that doesn’t work you will be adjusting, but, just as a hint, you can always look at the contrast enema and see how much volume the radiologist used to fill the entire colon, and you can use a little less than that because during your enema you’re not expecting to fill the entire colon. You’re mainly concentrating on cleaning the rectum and the left colon, as we expect that the stool in the right colon will take 24 hours to reach the rectum. So, for example, if the radiologist used 500 mL during the contrast enema, you can start your enema, your first one, at 400 mL and some irritant like glycerin, for example 20 mL of glycerin. And the key to succeed on the bowel management is to adjust the enema on a daily basis. We adjust it based on the parent or patient report and also looking at the abdominal radiograph is the only objective way to know that the enema indeed cleaned the colon or not.

Dr. Ponsky: So, you mentioned that the parents or the patient report back to you. Obviously the communication is important, but what do you want them to report to you?

Dr. Bischoff: The enema should be done at the same time every day and the entire process, enema administration, holding time, and evacuation should last for one hour. In the report we want to know how the child tolerated the enema, how long the entire process lasted, if the child is clean in the underwear or if the child is having accidents. We call accidents when there is passage of stool in the underwear. If there were accidents, we want to know the characteristics of it: how much, at what time (or times) after the enema, if it was real stool or just clear liquid. Based on the report and the radiograph, we make changes for the next day. For example, if the child had a real stool accident, and the abdominal radiograph is not clean, that means that the enema that I prescribed did not clean the colon enough. Therefore, I should increase the concentration. For example, increase the amount of glycerin.

Dr. Ponsky: You don’t increase the volume or the frequency. You increase the concentration of the glycerin.

Dr. Bischoff: No. The frequency: never. It’s always just once a day.


Malone stoma (39:48)


Dr. Ponsky: Okay, that’s great. You found the perfect enema for the child and the child is completely clean in the underwear with daily enemas, so now what?

Dr. Bischoff: That’s the question that the parents ask us all the time: Is that it? Are we doing that for their whole life? If we determine that the child is totally fecally incontinent with no bowel control and we’ll need enemas for life, and we already succeeded with bowel management through the rectum and now the child is growing and he or she doesn’t like that the mother or father is doing the enema, they want to become more independent, that’s when we offer them the Malone procedure as an antegrade way to give the enema. It is very important to emphasize that the Malone procedure or appendicostomy is not the treatment for the fecal incontinence. The treatment for the fecal incontinence is finding the enema that works for the child. The appendicostomy will just give them more independence. So normally we do it when the child asks for it, when the child wants to do the enema by him or by herself. The other scenario is for a child who has borderline bowel control. In that case, we found the enema, it works, the family goes home, spends a year, and we tell them every year, during your summer vacation for example, come back so we can try to stop enemas and test if the child has bowel control or not. If the child succeeds to stop the enemas, great, that’s it. If the child is enema-dependent then again we will follow the same pathway and offer an appendicostomy.


Bowel management for constipation (41:33)


Dr. Ponsky: This has been, so far, a really great review of anorectal malformations and really the bowel management, which I love listening to because I know that we have a lot of angst about it and our time is almost up but before we finish can you just quickly tell us about the bowel management for constipation in a child that does have bowel control.

Dr. Bischoff: Perfect. It takes us one week to find out the amount of laxative that a child needs on a daily basis in order to adequately empty his or her colon. It is very important that it is radiologically demonstrated. The first step also consists of getting a contrast enema to try to evaluate the magnitude of the constipation that we are dealing with. Many of our children come to us fecally impacted, so before trying to determine the laxative dosage, it’s very important to disimpact them. Otherwise, they will have the worst cramps of their lives and they will probably not come back. Our disimpaction protocol consists of 3 enemas per day for 3 days, and I can tell you that most of the children are disimpacted after day 3. After day 3, we get an abdominal x-ray to prove that the patient is disimpacted. If not, then we admit them, place a nasogastric tube, and run GoLYTELY for two days besides the enema. If they are still impacted, then we do disimpaction under anesthesia, which is extremely unusual. I can tell you that probably in the past 8 years, I think we have disimpacted under anesthesia 4 children at the most. So, the majority of them get disimpacted in the first portion of the protocol, with the 3 enemas per day for 3 days. Once the radiograph is clean, then we empirically choose an amount of laxatives, our preference is a senna-based one, and for the next 24 hours the child should be observed. So let’s suppose that 24 hours go by and the child has no bowel movement. That means that the dose that I selected was not enough. In that case I am going to give an enema to get rid of the stool that the child produced that day because you don’t want her or him to get impacted again and then we’re going to increase the dose of laxative at the same time. The other scenario is that 24 hours went by and the child had multiple diarrhea-like bowel movements. That means that the laxative dosage that I chose was too much, so we’re going to decrease the dose for the next day. Throughout the week we get the report from the parents consisting of the number of bowel movements, consistency of bowel movements, and also we look at the abdominal x-ray film because we want to compare and be sure that the amount of stool between one day and the next is not increasing. If the amount of stool is increasing, that means that the laxative dosage must be also increased.

Dr. Ponsky: Andrea, you mentioned senna, and I know this might be a tough question, but can you give me an idea, maybe based on size or age or just maybe it’s the same for everyone, how you start? Is it usually once a day? What’s the usual dose?

Dr. Bischoff: We always do once a day. Normally we prefer the end of the day, like 6:00 pm, so it will produce a bowel movement in the next day. The dosage, again, is trial and error. So we go from, and I can tell you our range, so from 8.8 mg of senna up to 175 mg of senna. So it can be a very high amount.

Dr. Ponsky: Do you start with the lowest dose first?

Dr. Bischoff: No. We look at the contrast enema and, based on the contrast enema, we empirically decide how much we’re going to start with.

Dr. Ponsky: I guess once someone starts a bowel management program they’ll get more comfortable with an idea of where to start once they start seeing it.

Dr. Bischoff: Absolutely.

Dr. Ponsky: Andrea, this has been very helpful for me. I love your answers because I think it’s going to be something I’ll be going back to and listening every time I have a patient.

Dr. Bischoff: I hope it’s not before bedtime.

Dr. Ponsky: No this will keep me awake instead of putting me asleep. This has been really helpful. And I actually tell you I think this is going to be helpful for not just pediatric surgeons but for the whole management team. I think that the nurses, the midlevels, the pediatrician, neonatologists, and the radiologists would really love to listen to this and I think it’s been a huge help. So, I want to thank you for taking time out of your day to explain to me and the rest of the world about how to manage these difficult problems.

Dr. Bischoff: Thank you so much, Todd. It has been a pleasure. And if there are any questions, don’t hesitate to contact me.

Dr. Ponsky: Perfect. Actually I may ask you if you can tell us, is there a number or an email that pediatric surgeons or pediatricians can contact your center, or you personally, to get information?

Dr. Bischoff: Absolutely. My personal email is and the colorectal center email is