The morbidity of constipation in patients with anorectal malformations

Background

Constipation in anorectal malformations (ARM) is extremely common, particularly in the lower types. Failure to adequately treat it can lead to significant morbidity.

Methods

From our series of over 2000 patients with ARM, we reviewed 398 with good prognosis for bowel control and a tendency toward constipation; rectoperineal fistula (63), rectovestibular fistula (114), rectobulbar urethral fistula (104), imperforate anus with no fistula (46), rectal atresia or stenosis (9), and cloaca with a common channel below 3 cm (62). Those lost to follow-up, not yet toilet-trained (<3 years old), or with poor prognostic features were excluded. We compared morbidities in patients we operated on and managed primarily (group A, n = 268) to those managed at other institutions who suffered from constipation or incontinence and were referred to us for treatment (group B, n = 130). Those we managed primarily were subjected to an aggressive senna-based laxative program, started after their primary repair or after colostomy closure.

Results

Morbidities associated with constipation were higher in the referral group and included fecal impaction (7.8% vs 38.5%), overflow pseudoincontinence (4.9% vs 33.8%), and megacolon (14.6% vs 54.6%). A loop or transverse colostomy (4.9% vs 9.2%), stoma or anorectal stricture, or a stenotic fistula (2.2% vs 28.5%) were contributing factors. Adequate laxative treatment with, in certain cases, resection of a megarectosigmoid (2.6% vs 23.1%) enabled many pseudoincontinent children to achieve bowel control (reported previously). Unneeded colorectal biopsies (1.9% vs 16.2%), Hirschsprung's-type pullthroughs (0% vs 3.1%), and, in retrospect, unneeded antegrade continent enema procedures (0% vs 3.1%) were higher in Group B. Overall, 19.8% of Group A and 66.2% of Group B experienced constipation-related morbidities.

Conclusion

The morbidity of constipation in ARM includes fecal impaction, megacolon, incontinence, and performance of unneeded surgeries. Inadequate treatment, the type of the original colostomy, and postoperative anal or stomal stricture as well as stenotic fistulae were key contributing factors. Children with ARM and good prognosis for bowel control are at the greatest risk for severe constipation and its consequences. With recognition and aggressive, proactive treatment, we have found that these morbidities can be reduced.