Ileal pouch-anal anastomosis (IPAA), also referred to as a J-pouch procedure, is a colorectal surgery technique performed in patients undergoing proctocolectomy or proctectomy, where a reservoir ("neorectum") is made with a segment of distal ileum just before its anastomosis with the anal canal. Variations of the technique using a W-pouch or S-pouch have been largely discontinued. 

The most common indications for this operation in the setting of proctocolectomy are ulcerative colitis and familial adenomatous polyposis syndrome (FAPS). The procedure is performed either as a two- or as three-stages operation:

• two-stages: proctocolectomy, J-pouch, and diverting ileostomy in one go, followed by a second operation to restore intestinal continuity
• three-stages: colectomy and ileostomy in the first approach, followed by a second surgery for proctectomy and loop ileostomy, and, lastly, final ileostomy reversal 

Radiographic features

Imaging is normally performed only in the assessment of postoperative complications, which include:

• anastomotic leak
• anastomotic stricture
• pouch prolapse 
• efferent loop syndrome: torsion or volvulus at the level of the pouch-anal anastomosis 
• pouchitis
  • pouch inflammation possibly related to infection related to different flora in the distal small bowel mucosa
  • may respond to antibiotics, depending on aetiology
• Crohn disease 
  • eventually, the presumed ulcerative colitis is discovered to represent Crohn disease given the recurrence of the inflammatory disease in the pouch
  • can be difficult to differentiate to postoperative complications or pouchitis
  • tend to involve the pre pouch ileum and anal canal