Less common causes of rectal bleeding include: Anal cancer. Angiodysplasia (abnormalities in the blood vessels near the intestines) Colon cancer. Colon polyps. Crohn's disease. Diarrhea. Diverticulosis (a bulging pouch that forms on the wall of the intestine).
Chronic rectal bleeding. Bleeding may be overt when noticed by the patient or occult when invisible blood loss is detectable by faecal occult blood test only. Management of rectal bleeding involves exclusion of a colorectal neoplasm and finding the cause of the bleeding. Classification and causes of chronic rectal bleeding are given in Table
Rectal bleeding often begins in the presence of chronic constipation due to the ongoing straining and pressure on the walls of the rectum. Bleeding may also occur when there is chronic diarrhea, because of the irritation and inflammation that this causes in the tissues.
Chronic rectal bleeding. So when I pass the stool, the feces are perfectly normal, not mixed in with blood or looking tarry. The way I understand it, that when I pass the stool, it somehow manages to hurt my anal area and causes a small wound, which explains why several drops of blood fall on the toilet several seconds after the stool passes and goes into the toilet bowl. An anal fissure, a split or tear in the lining of the anus, causes bleeding and burning pain after bowel movements. The usual cause is passing a very hard stool. The pain is caused by a spasm of the sphincter muscle.
There are a variety of causes of rectal bleeding. Common causes include hemorrhoids, anal fissure, diverticulosis, infection, inflammation (IBD or irritable bowel disease, Crohn's disease, colitis), blood vessel problems (angiodysplasia). Other causes of rectal bleeding include polyps, tumors.