What causes stool bleeding after colonoscopy?

The causes of stool bleeding after colonoscopy may be related to intestinal mucosal damage, anal fissure, internal hemorrhoid rupture, etc. The specific analysis is as follows:

1. Intestinal mucosal damage

Due to the relatively fragile intestinal mucosa, and colonoscopy is an invasive operation, it may cause intestinal mucosal damage, causing submucosal vascular rupture, and stool bleeding.

2. Anal fissure

Due to poor or small anal flexibility of patients, colonoscopy surgery will cause tissue rupture around the anus, resulting in the above phenomenon.

3. Internal hemorrhoid rupture

Due to colonoscopy surgery, internal hemorrhoids may be stimulated, resulting in blood vessel rupture on the surface of internal hemorrhoids, causing a large amount of blood exudation.