Ileal pouch-anal anastomosis, or J pouch, surgery has become the procedure of 
choice for treatment of medically refractory ulcerative colitis and familial 
adenomatous polyposis. Overall, this operation is associated with a low rate of 
postoperative morbidity and good long-term function. However, when complications 
develop, there is a heavy reliance on imaging to facilitate an accurate 
diagnosis. Reported postoperative complication rates range from 5% to 35%. 
Complications generally can be categorized as structural, inflammatory, or 
neoplastic conditions. Structural complications include leaks, strictures, 
afferent and efferent limb syndromes, and pouch prolapse. Inflammatory 
conditions include cuffitis, pouchitis, and Crohn disease of the pouch. In 
addition, a variety of neoplastic conditions can develop in the pouch. Overall, 
pouchitis and leaks are the most common complications, occurring in up to 50% 
and 20% of individuals, respectively. Many imaging modalities are used to 
evaluate the J pouch and associated postoperative complications. The indications 
and various surgical techniques for J pouch surgery, normal postoperative 
appearance of the pouch, and most common associated complications are reviewed. 
In addition, the various imaging findings associated with J pouch surgery are 
described and illustrated. The radiologist's familiarity with the potential 
complications of the pouch can facilitate appropriate imaging, hasten an 
accurate diagnosis, and aid in rendering proper management. ©RSNA, 2018.