Evaluation of the Patient with Anorectal Malformation Who Was Previously Repaired But Not Doing Well
The surgeon should start by evaluating the patient’s potential for bowel control by calculating the anorectal malformation index, which consists of 3 parts, with numerical values given to each part. The three parts consist of the type of anorectal malformation, the sacral ratio calculated on AP view of the sacrum, and the quality of the spine seen on spine MRI. The surgeon can then collect more information with a full imaging workup, including a pelvic MRI to evaluate for a remnant of original fistula (ROOF) and a contrast enema to evaluate for any stricture or dilation. Then, the patient should proceed to an exam under anesthesia to evaluate the anatomy for any abnormalities that would require a reoperation. If abnormal anatomy is found, then the surgeon should consider whether the patient could benefit from a Malone and/or a colon resection at the time of the re-operation to fix the abnormality. If the anatomy is good and there is no surgical intervention needed, then the patient can proceed with a bowel management program that would either involve a laxative trial or an enema regimen.
View the anorectal malformation treatment algorithm (PDF).
Evaluation and Management of a Hirschsprung Patient Who Has Had a Pull-through But is Not Doing Well
The surgeon should start by evaluating the patient’s main category of symptoms, which can fall into either obstructive symptoms or fecal soiling.
Symptoms of patients with obstruction can take various forms and include failure to thrive, recurrent episodes of enterocolitis, chronic abdominal distension, or longstanding history of severe constipation that is refractory to medical management. These patients should be evaluated first with a contrast enema, followed by an exam under anesthesia with rectal biopsy to look for a transition zone. At the time of EUA, the surgeon is looking at the anatomy to make sure that the dentate line is intact, and that the sphincters are normal-appearing and not patulous. The pathology of the biopsy should also return normal, meaning the presence of ganglion cells, absence of hypertrophic nerves, and a positive calretinin stain to indicate that there is not a transition zone. If the contrast enema or the EUA shows an abnormality, then the patient will need a redo pull through for the reasons listed. The surgeon should also consider a Malone placement at the time of redo pull-through. If the anatomy, pathology, and contrast enema do not show any abnormalities that would warrant a reoperation, then the surgeon should evaluate the sphincter for any dysfunction and determine if a trial of Botox would improve the obstructive symptoms. If there is no sphincter dysfunction, then the patient should initiate a bowel management program with optimization of either medical or mechanical treatment.
For patients who have symptoms of fecal soiling, without a history of constipation, the physician can start the evaluation with a contrast enema and a EUA with 3D anal manometry to evaluate the sphincter function. In cases of purely fecal soiling, it is unlikely the patient will need a biopsy, as there is unlikely to be a transition zone causing an obstruction. At the time of EUA, the surgeon should evaluate for an intact dentate line and good sphincter function. If these are normal, the patient should have an aggressive bowel management program for ongoing medical management of fecal soiling. If the EUA or 3D AMAN is abnormal, the surgeon should consider a procedure for sphincter reconstruction and/or a Malone for future optimization of bowel management.
View the Hirschsprung treatment algorithm (PDF).
Management of a Patient with Functional Constipation Who Has Failed Medical Management
For a patient with a longstanding history of functional constipation, the physician should start with a contrast enema to evaluate for the degree of colonic dilation as well as any segments that are redundant. The patient should then undergo anorectal manometry (AMAN) to check for a RAIR (rectoanal inhibitory reflex) as well as the resting pressure of the sphincters. If a RAIR is absent, or the patient has high resting pressure, then at the time of AMAN, the patient should get a rectal biopsy and consider injection of botox at that time. The patient may also benefit from pelvic floor physiotherapy. Of note, patients who are very young may not be able to undergo AMAN with reliable results or patients who cannot follow instructions during the AMAN. These patients may benefit from a rectal biopsy to definitively rule out Hirschsprung disease.
For patients who have a RAIR or exhibit low resting pressure, a biopsy is not needed. These patients should then proceed with colonic manometry to guide the next intervention. Patients with functional constipation can either be managed with medical treatment or surgical intervention. Medical treatment would start with optimizing laxative therapy or a trial of enemas. For surgical intervention, a Malone can be placed to facilitate antegrade flushes, with ongoing titration of the flush regimen on an individual basis. If the patient is successfully managed with flushes, after about 6-12 months, the patient can eventually be transitioned to laxative therapy. If the flushes are unable to manage the patient’s constipation, then additional surgical intervention may be needed to resect the colon. An additional study prior to surgery is to assess for reflux of the flush into the terminal ileum with a contrast study, as a possible cause of flush intolerance by the patient. The extent of resection may be guided by the colon manometry results, and options include a segmental sigmoid resection if there is focal segmental dysfunction, extended colon resection if there is significant dilation or redundancy, or a total colon resection if there is poor motility throughout the entire colon.
View the functional constipation treatment algorithm (PDF).
Bowel Management Program for Fecal Incontinence and Soiling
Patients with a diagnosis of Hirschsprung disease or anorectal malformation who are not doing well with stooling after surgical repair will benefit from a Bowel Management Program to optimize medical management of either their constipation or soiling. There are two main options for bowel management, separated by either mechanical treatment or medical treatment. The mechanical treatment utilizes enemas, either performed retrograde or as antegrade flushes. They are usually given with a solution of normal saline, but water can be used as well. Glycerin is the main ingredient mixed with the solution but soap can be added to the flush as well.
Medical management consists of treatment targeted at either hypomotility or hypermotility. For patients with hypomotility, a good combination to start patients on is senna and water-soluble fiber. Sometimes, we will put patients on Miralax in the immediate post-operative period for about a month to avoid any constipation, but stop it after 1 month and have patients continue with the senna. For patients with hypermotility, we recommend to families a constipating diet, as well as water-soluble fiber. Medications for slowly down motility can also be used. If patients continue to struggle with hypermotility, small volume enemas can be used to help keep patients clean.
View the bowel management treatment algorithm (PDF).