Ileosigmoid knot: Diagnostic value of CT in a rare double-volvulus entity

Ileosigmoid knot (ISK) is a rare, life-threatening cause of intestinal obstruction characterized by a double volvulus involving the ileum and sigmoid colon. This case report highlights distinctive CT findings that facilitate early diagnosis and prompt surgical intervention. A 75-year-old male with chronic constipation and prior midline laparotomy presented with acute bowel obstruction without peritonitis. CT revealed a whirl sign involving both superior and inferior mesenteric artery branches, adjacent ileal loops, and an obliquely oriented torsion, suggestive of ISK. Emergency laparotomy confirmed a Type I ISK, enabling timely detorsion and prophylactic sigmoidectomy before ischemic complications developed. ISK should be suspected when CT demonstrates a whirl sign incorporating both superior and inferior mesenteric artery branches, adjacent ileal loops, and a torsion extending across multiple contiguous slices. These findings distinguish ISK from isolated sigmoid volvulus, guiding appropriate surgical management to optimize outcomes in this rare entity.