Ileostomy

An ileostomy is an artificial stoma formed between the ileum and abdominal wall. Indications for its formation include distal obstruction, usually of the colon, inflammatory bowel disease, and familial adenomatous polyposis. Common forms include end ileostomies and loop ileostomies.

A permanent end ileostomy is usually sited in the right iliac fossa. A skin incision 2.5-3 cm is made and then a cruciate incision is made into the rectus sheath. The ileum is clamped and passed through the incision. The formation of a peritoneal tunnel decreases the risk of herniation or prolapse. The ileum is everted into a spout and sutured to the skin. The surrounding abdominal wound is closed.

A loop ileostomy is usually for more temporary use, e.g. for decompression with a distal obstruction. A circular disc of skin and fat is excised, and a cruciate lesion is made in the anterior rectus sheath. The rectus abdominis is split and the fascia and peritoneum are opened. A loop of ileum is selected so that it is unlikely to be in tension at its final site. A rubber sling or absorbable subcutaneous bridge of fibrin is passed through the mesentery at the apex of the loop, and the main wound is then closed around it. The distal limb is then divided close to the skin edge around its circumference, and the bowel wall is folded back to form a spout. Sutures are then used to anchor the skin and mucosa.