A 78-year-old man presents to the emergency department with acute onset of bright red blood per rectum. Symptoms started 2 hours earlier, and he has had three bowel movements since then with copious amounts of blood. He denies prior episodes of rectal bleeding. He notes dizziness with standing but denies abdominal pain. He has had no vomiting or nausea. A nasogastric lavage is performed and shows no coffee ground emesis or blood. Lab evaluation reveals hemoglobin of 10.5 g/dL. What is the most likely source of the bleeding?A. Internal hemorrhoids
Bright red blood per rectum typically indicates a lower GI source of bleeding, although occasionally a high-output upper GI bleed may result in bright red blood. Diverticular bleeds can be massive. Although 80% resolve spontaneously, bleeding recurs in one-fourth of patients. Colonoscopy would be the diagnostic method of choice if diverticular bleed is suspected, but bleeding has frequently stopped before visualization occurs. With recurrent diverticular bleed, hemicolectomy may be necessary. Although nasogastric lavage has lost favor as a diagnostic maneuver, in this case, a negative lavage decreases the likelihood of a significant bleed from the stomach or esophagus. Neither internal hemorrhoids nor sessile colonic polyps usually results in hemodynamically significant acute bleeding. A Dieulafoy vessel is a largecaliber vessel close to the mucosal surface, most commonly located on the greater curvature of the stomach. Mallory-Weiss tears occur as a result of traumatic injury at the gastroesophageal junction from forceful vomiting and may lead to large-volume blood loss. Both of these lesions would be associated with evidence of upper GI bleeding.