**Question:** True about solitary rectal ulcer syndrome is **except A**.

**Core Concept:**
Solitary rectal ulcer syndrome (SRUS) is a condition characterized by the presence of a single ulcer in the rectum, typically caused by a combination of mechanical and/or ischemic factors. The ulcers are usually located in the distal rectum, near the anus, and are often associated with constipation or fecal impaction.

**Why the Correct Answer is Right:**
SRUS is characterized by the presence of a single ulcer in the rectum, which is the main reason why option A ("Solitary rectal ulcer syndrome is characterized by multiple ulcers") is incorrect. Multiple ulcers are more commonly associated with conditions like Crohn's disease or radiation proctitis, rather than SRUS.

**Why Each Wrong Option is Incorrect:**

A. Solitary rectal ulcer syndrome is typically caused by mechanical factors, such as rectal mucosal ischemia or irritation, and not by ischemic factors alone. Therefore, option B ("Solitary rectal ulcer syndrome is caused by ischemic factors") is incorrect.

B. Although constipation or fecal impaction can contribute to the development of SRUS, the correct answer should emphasize the presence of a single ulcer. Option C ("Solitary rectal ulcer syndrome is caused by a combination of mechanical and ischemic factors") is incorrect because it does not emphasize the single ulcer aspect of the condition.

D. Solitary rectal ulcer syndrome is typically associated with irritation and ischemia of the rectal mucosa. Although it may be related to anal fissure, option D ("Solitary rectal ulcer syndrome is caused by anal fissure") is incorrect, as the condition is primarily caused by mechanical factors and not anal fissure.

**Clinical Pearl:**
Solitary rectal ulcer syndrome should be considered in patients presenting with rectal pain, bleeding, and a single ulcer in the rectum, particularly when associated with constipation or fecal impaction. A combination of mechanical and ischemic factors is responsible for the development of SRUS, and anal fissure is not the primary cause.

**Correct Answer:**
**Correct Answer: Solitary rectal ulcer syndrome is caused by a combination of mechanical and ischemic factors.**

In summary, SRUS is a condition resulting from mechanical and ischemic factors affecting the rectal mucosa, leading to a single ulcer in the rectum. This condition should be considered in patients presenting with rectal pain, bleeding, and a single ulcer in the rectum, particularly when associated with constipation or fecal impaction.