The Continence Predictor Index

March 31, 2015
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Physicians can now use a standardized approach to predict continence in children with anorectal malformations/imperforate anus.

As soon as a child with an anorectal malformation/imperforate anus is born, it is explained to parents that their baby has no anal opening and one needs to be surgically created. Instead of worrying whether the surgeon can create an ideal anus, parents almost universally want to know whether or not their child will have fecal continence. They want to know whether the child’s new anus will work and if their child will be able to wear normal underwear.

It became clear to us that parents need a guide to predict their child’s likelihood to achieve continence. For patients with good potential, potty training strategies along with laxative treatment is used. For patients with poor potential for continence, a bowel management program can successfully get them clean. So, should parents start to potty train the child at age 3? Or should they plan to participate in a bowel management program to achieve stool cleanliness?

My colleagues and I at the Center for Colorectal and Pelvic Reconstruction at Nationwide Children’s Hospital, have devised an index based on a patient’s anatomy that we believe will predict that child’s likelihood of being continent by age 3 years. Ideally, this tool will allow doctors to make a continence prediction even in the first few days of life.

Predicting Continence in Children With ARM

In my view, all children with anorectal malformations (ARM) should be clean for stool at the start of nursery school, the typical age of potty training, either because they possess all the elements of continence or because they can be clean with a bowel management program. Substantial advances in the surgical treatment of ARM have occurred in the last several decades. Techniques have improved, and a dramatic reduction in complications and better success with achieving continence is seen.

We have found that, with knowledge of (1) the anatomic features of the type of malformation, (2) the quality of the sacrum (tailbone) and (3) the quality of the spinal cord, we can predict a patient’s potential for continence. Our Continence Predictor Index uses these three factors to create a custom score. We have known through experience for many years that higher malformations, along with associated sacral and spinal abnormalities (such as tethered cord or spina bifida), predict worse continence outcomes, but we sought a more objective assessment.

Now, we are developing knowledge of the impact of each of these factors.

With the advent of the CP Index, we felt that our ability to predict continence even prior to surgical intervention could be an important component in counseling families and setting expectations. In addition, benchmarking outcomes based on the particular ARM type would be an important tool to ensure minimum quality standards and improve the quality of care overall. Moreover, that standard could be compared across our international partner institutions.

Using the Continence Predictor Index

To predict the likelihood of a child developing normal bowel control, we need to know the type of anorectal malformation and the type of sacrum and spine that they have. Newborn ARM patients typically undergo routine investigations, including kidney investigation (ultrasound), spinal assessment (spinal ultrasound and/or MRI) and sacrum evaluation (x-rays of the sacrum). The ARM type is either diagnosed by clinical exam or demonstrated on a radiology study called a distal colostogram.

Once we have this information for a patient, we can calculate a CP Index score and make a continence prediction. Our preliminary data collection indicates that good scores in all three categories predict that continence will be achieved. Similarly, when poor scores are found in all three categories, continence will be a challenge and bowel management is likely needed.

We are still studying the group of patients with results that do not fall on the high and low ends of the CP Index, and don’t yet know specific predictions for those patients.

Please visit our Center for Colorectal and Pelvic Reconstruction website to learn more about our efforts and to view a copy of our Continence Predictor Index.


Join the conversation. What other factors are important to consider in developing a prediction of continence for children with ARM?


Marc A. Levitt, MD, is an internationally renowned colorectal surgeon and serves as the surgical director for the Center for Colorectal and Pelvic Reconstruction at Nationwide Children’s Hospital.  He has directed numerous colorectal training courses attended by established surgeons and surgical trainees from all over the world. Dr. Levitt dedicates much of his free time to educational trips around the world to train surgeons in his complex surgical techniques. He has published more than 120 manuscripts and 60 book chapters and has delivered more than 300 national/international and 100 local/regional presentations of his work.