Colonic Ischemia Secondary to Vascular Steal Phenomenon

Arteriovenous malformations (AVMs) of the mesenteric vasculature are rare, and patients often present with nonspecific gastrointestinal symptoms, presenting diagnostic challenges. We present a case of severe colonic ischemia secondary to an inferior mesenteric artery arteriovenous malformation in a 62-year-old man with pain, diarrhea, general malaise, and unintentional weight loss, who was diagnosed on computed tomography angiography after failing conservative management for presumed infectious colitis. Our case highlights diagnostic challenges due to its relatively nonspecific symptoms and rarity, and the need for early recognition to prevent complications of bowel ischemia and bleeding.