What is the most common cause of lower GI bleeding?

Diverticulosis is identified as the most common cause of lower GI bleeding. It is a condition characterized by the presence of small pouches (diverticula) that form in the walls of the colon. These pouches can become inflamed or bleed, often leading to significant gastrointestinal hemorrhage. The reason diverticulosis is so prevalent as a cause of lower GI bleeding relates to its widespread occurrence in the population, especially among older adults.

While ulcerative colitis, inflammatory bowel disease, and angiodysplasia are all important considerations in the differential diagnosis of lower GI bleeding, they are less frequently the primary underlying cause compared to diverticulosis. Ulcerative colitis is a form of IBD that can lead to bleeding as well, but it is less common in the general population when considering overall incidence rates. Angiodysplasia, which involves abnormal blood vessels in the colon, can also result in bleeding, but it typically represents a smaller proportion of cases in comparison. Thus, diverticulosis stands out as the most common and significant contributor to lower GI bleeding in clinical practice.