Which description defines the construction of an ileoanal reservoir?

• A. Excision of jejunum and ileum
• B. Construction of an internal pouch by removal of the colon and attachment of a segment of ileum to the anus
• C. External drainage to a bag
• D. Constructing a pouch from stomach

Answer: (B)

Forming an internal reservoir from ileum that is attached to the anus after removing the colon is what defines an ileoanal reservoir. This procedure, often called an ileal pouch-anal anastomosis, uses a segment of ileum folded into a pouch to store stool inside the body, with the anal sphincter preserved to allow continence. The colon is removed, or nearly so, and the ileal pouch is surgically connected to the anus, creating a path for defecation without an external bag. This contrasts with external drainage (an ileostomy) where waste exits through a stoma into a bag, and with using stomach tissue, which would be a gastric pouch, not an ileal reservoir. The description given—constructing an internal pouch from ileum and attaching it to the anus after colonic removal—best fits the ileoanal reservoir.