A 21-year-old male complains of abdominal pain. His abdomen is soft to palpation, and the pain is greatest in the left upper quadrant. He reports maroon stools for the past two days. Which is most likely suspected?

• A. Upper GI bleeding
• B. Peritonitis
• C. Lower GI bleeding
• D. Renal calculi

Answer: (A)

Stool color is a key clue to where GI bleeding is coming from. Maroon stools are suggestive of a lower GI source because blood has not been digested much as it passes through the tract, so you don’t get the classic black, tarry appearance of melena seen with upper GI bleeds. An upper GI bleed more commonly presents with hematemesis or melena, not maroon-colored stool. The left upper quadrant location of pain doesn’t definitively point to an upper GI source, but the stool color strongly points toward bleeding in the lower GI tract, such as the colon or distal small intestine. So the scenario fits a lower GI bleed best.

If the question asked about what would point away from this, note that peritonitis tends to cause a rigid, tender abdomen with rebound, not just localized LUQ pain and maroon stools. Renal calculi causes sudden, intense flank or groin pain, not a primary GI bleed picture.