Abstract
The ileosigmoid knot is a rare cause of intestinal obstruction in which the ileum wraps around the base of the sigmoid colon. A 59-year-old man was admitted to our hospital with severe abdominal pain of sudden onset. Abdominal computed tomography revealed the dilatation of the sigmoid colon and small intestine, ascites, and medial deviation of the descending colon. A dilated loop of the sigmoid colon like a volvulus was located in the right hemiabdomen and distended loops of the small intestine in the left hemiabdomen. We suspected an ileosigmoid knot and performed an emergency operation. Laparotomy demonstrated a sigmoid volvulus surrounded by a gangrenous loop of small bowel. We resected the sigmoid colon and small intestine. These were key findings to make the preoperative diagnosis that both sigmoid colon and small intestine were dilatated and the loop of the small intestine lay an the left side of the abdomen, with the loop of the sigmoid colon an the right side.
