Background: Many reports have described sigmoid volvulus, but fatal hemorrhagic shock resulting from the rupture of the involved artery has not been reported as a complication of a sigmoid volvulus.
Case Report: A 71-year-old man with slight abdominal pain and obstipation in hypotension died at a nursing home without seeing a doctor. At autopsy, a mesenteric hematoma and hemoperitoneum was observed with approximately 1,000 ml of blood in the abdominal cavity. The sigmoid colon and the mesentery were twisted at an adhesion site of a sigmoid colon to an ileum, and the condition was determined to be a sigmoid volvulus. The volvulus was observed to be loosened. The inferior mesenteric artery was incorporated into the twisted part of the mesentery, but remained patent, and its peripheral branch near the hematoma ruptured without histological abnormality.
Conclusions: Since ischemic-reperfusion injury occurs with a temporarily occluded artery, the acute re-loading of blood flow may injure the distal vessels after spontaneous reduction of compression by loosening of the volvulus.

Keywords: Mesenteric Arteries - pathology, Intestinal Volvulus - pathology, Colon, Sigmoid - pathology, Blood Vessels - pathology, Rupture, Shock, Hemorrhagic - pathology