A 68-year-old man with recent episodes of hypotension develops sudden left-sided abdominal pain followed by passage of dark red blood mixed with stool. Colonoscopy shows a single segment of edematous, cyanotic mucosa with subepithelial hemorrhage beginning just proximal to the descending colon, with sparing of the rectum. Which site was most likely compromised?

• A The hepatic flexure
• B Sudeck point at the rectosigmoid junction
• C The ascending colon near the marginal artery origin
• D Watershed zone at the splenic flexure (Griffiths point) ✓

Explanation

Ischemic colitis classically affects watershed areas with poor collateral supply. The splenic flexure, at Griffiths point between the terminal branches of the middle colic and left colic arteries, is the single most commonly involved segment. Sudeck point at the rectosigmoid junction is the second watershed zone. Rectal sparing occurs because the rectum has dual supply from the superior and inferior mesenteric circulations.

Reference: Sabiston Textbook of Surgery, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.