Crohn's of the Pouch: Now What?

Total proctocolectomy and ileal pouch anal anastomosis (IPAA) is the gold standard surgical treatment for the majority (∼90%) of ulcerative colitis (UC) patients. In cases of carefully selected Crohn's colitis patients without small bowel or perianal involvement an "intentional IPAA" may be a viable option for disease resection and restoration of intestinal continuity. More commonly, Crohn's is incidentally found either in the resection specimen or, more commonly, when inflammatory complications subsequently arise after pouch construction for UC or indeterminate colitis. These incidental Crohn's pouches may be diagnosed early or late period post-IPAA. Crohn's may manifest within the pouch, in the proximal small bowel, and/or distally in the rectal cuff or anus. Like intestinal Crohn's, Crohn's disease of the pouch may be of an inflammatory, fibrostenosing, or fistulizing phenotype. Treatment depends on the phenotype and includes medical treatment, most commonly in the form of tumor necrosis factor inhibitor medications; however, the newer small molecules offer a potential treatment for these patients. Surgery first entails treating the sequelae of Crohn's and is typically staged. In up to 60% of Crohn's pouches, particularly in fistulizing disease and/or recalcitrant perianal disease, the pouch fails and must be defunctioned or excised. In patients with Crohn's pouches in situ long term, outcomes including quality of life are comparable to patients who underwent IPAA for UC.