Most common cause of colonic obstruction is:
**Core Concept**
Colonic obstruction is a condition where the normal flow of stool through the colon is blocked, leading to severe abdominal pain, vomiting, and constipation. The most common causes of colonic obstruction are related to structural abnormalities or mechanical blockages within the colon.
**Why the Correct Answer is Right**
Diverticulitis is a condition where diverticula, small pouches in the wall of the colon, become inflamed and can cause a complete or partial blockage of the colon. This is often due to the formation of a diverticulum that becomes obstructed by a blood clot, fecal matter, or a foreign body. The inflammation and subsequent scarring can lead to a narrowing of the colon, known as a stricture, which can cause a complete obstruction.
**Why Each Wrong Option is Incorrect**
**Option A:** Volvulus is a condition where a loop of intestine twists around its mesentery, cutting off blood flow and causing obstruction. However, it is less common than diverticulitis as a cause of colonic obstruction.
**Option B:** Carcinoma of the colon is a rare cause of colonic obstruction, especially in the absence of other symptoms like weight loss or change in bowel habits.
**Option C:** Hirschsprung's disease is a congenital condition characterized by the absence of ganglion cells in the distal colon, leading to severe constipation. However, it is more common in children and is not the most common cause of colonic obstruction in adults.
**Clinical Pearl / High-Yield Fact**
Diverticulitis is often associated with a history of constipation, a low-fiber diet, and obesity, making it essential to maintain a high-fiber diet and regular physical activity to prevent this condition.
**Correct Answer:** A. Diverticulitis