A flap protruding from the anus can be considered for intestinal diseases such as hemorrhoids, rectal polyps and tumors. 1. Hemorrhoids: hemorrhoids can be divided into internal hemorrhoids, external hemorrhoids, mixed hemorrhoids three. All three can have the manifestation of protrusions, internal hemorrhoids can also be manifested as intermittent blood after defecation; external hemorrhoids can be anal discomfort, itching; mixed hemorrhoids for the simultaneous existence of internal and external hemorrhoids, protrusions mostly in the perianal area in the form of a plum blossom or a ring, known as annular hemorrhoids. 2. Rectal polyps: low polyps with tips can be prolapsed out of the anus. The polyps are substantial round polyps, with tips, movable. It is mostly seen in children. 3. Rectal tumor: low rectal cancer can also have anal protrusion manifestation, mostly accompanied by changes in defecation habit and stool character, weight loss, emaciation and other manifestations. If there is a mass protruding from anus, one should go to the hospital for comprehensive examination, such as anal diagnosis and proctoscopy, etc., so as to make a clear diagnosis and follow the doctor’s instruction for treatment.