Ileosigmoid knotting.

Ileosigmoid knotting (ISK) is the wrapping of the ileum around the sigmoid colon and its mesentery or vice-versa. The incidence of ISK is not well known, but it generally occurs in areas with a high incidence of sigmoid volvulus, and it is common in adult males. The etiology of ISK is controversial. The main symptoms are abdominal pain, distention, obstipation, and vomiting, while the main signs are abdominal distention and tenderness. There are no specific blood tests for diagnosing ISK. Plain abdominal X-ray radiographs demonstrate a dilated sigmoid colon and multiple small intestinal air-fluid levels. Abdominal CT demonstrates a twisted and dilated sigmoid colon with whirled sigmoid mesentery, in addition to twisted and dilated small intestinal segments. The accurate preoperative diagnosis of ISK is difficult. After rapid and prompt resuscitation, emergency surgery is needed in the treatment of ISK. In gangrenous cases, resection with primary anastomosis is preferred, while, in nongangrenous cases, untying of the knot may be performed as a sole surgical procedure, or a volvulus-preventing procedure may be added. The mean mortality rate for ISK is 6.8-8% in nongangrenous and 20-100% in gangrenous cases.