Most common cause of lower gastro intestinal bleeding is –
**Core Concept**
The most common cause of lower gastrointestinal bleeding is often related to **diverticulosis**, a condition characterized by the formation of small, bulging pouches (diverticula) in the digestive tract. This condition is prevalent in the Western population, particularly among the elderly.
**Why the Correct Answer is Right**
Diverticula are most commonly found in the **sigmoid colon** and can erode into blood vessels, leading to bleeding. The exact mechanism of bleeding in diverticulosis is not fully understood but is thought to be related to the erosion of a blood vessel within a diverticulum.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect as it's not the most common cause.
**Option B:** Incorrect, though it can cause bleeding, it's less common than diverticulosis.
**Option C:** Incorrect, more commonly associated with upper GI bleeding.
**Option D:** Incorrect, though a possible cause, it's not the most common.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that while diverticulosis is the most common cause of lower GI bleeding, other causes such as **angiodysplasia**, **inflammatory bowel disease**, and **colon cancer** should also be considered in the differential diagnosis.
**Correct Answer:** D. Diverticulosis.