Controversies in Crohn's Disease Before and After Pouch Surgery

BACKGROUND:IPAA is rarely performed in patients with a known diagnosis of Crohn's disease, although it may be done in highly selected patients with an absence of perianal disease or small bowel inflammation. Patients with a preoperative diagnosis of Crohn's disease are, however, at increased risk of developing Crohn's disease of the pouch. Crohn's disease of the pouch can also occur in people with a preoperative diagnosis of ulcerative colitis; however, it is unknown whether this phenotype is similar to classic Crohn's disease involving an intact bowel, or whether it is a distinct entity. OBJECTIVE:This study aimed to describe Crohn's disease of the pouch, including luminal inflammation, and fibrostenotic and perforating phenotypes, as well as management of these conditions. RESULTS:Crohn's disease of the pouch can present in similar ways as classic Crohn's disease, classified as either inflammatory, fibrostenotic, or penetrating. Criteria involving the diagnosis of Crohn's disease of the pouch are stringent to prevent unnecessary treatments, because a diagnosis of Crohn's disease after IPAA for presumed ulcerative colitis can cause mental anguish. Treatment of Crohn's disease of the pouch depends on the presenting phenotype, although therapies are similar to classic Crohn's disease. Endoscopic, or even surgical treatment, may be required for fibrostenotic and fistulizing diseases. LIMITATIONS:Crohn's disease of the pouch is a newly described disease of patients who undergo an ileoanal pouch anastomosis; and therefore, most of the evidence comes from retrospective trials in patients with an initial diagnosis of ulcerative colitis. CONCLUSIONS:While Crohn's disease of the pouch is controversial and perhaps a distinct disease within the spectrum of inflammatory bowel diseases, it nonetheless requires long-term medical therapy and close follow-up.