Blood in the stool can be concerning, whether you discover it while wiping after a bowel movement or from a test ordered by your doctor.

While blood in stool can signal a serious problem, it doesn’t always. Here’s what you need to know about the possible causes of bloody stools and what you — and your doctor — should do if you discover a problem.

Causes of Blood in Stool

Blood in the stool means there is bleeding somewhere in your digestive tract. Sometimes the amount of blood is so small that it can only be detected by a fecal occult test (which checks for hidden blood in the stool).

At other times it may be visible on toilet tissue or in the toilet after a bowel movement as bright red blood. Bleeding that happens higher up in the digestive tract may make stool appear black and tarry.

Possible causes of blood in the stool include:

Inflammatory bowel disease (IBD). If you have bloody diarrhea and pain that goes on for weeks, along with weight loss, IBD might be the reason. This long-term condition inflames parts of your digestive tract. Experts aren’t sure exactly why that happens. There are two main kinds of IBD: ulcerative colitis and Crohn’s disease.

Ischemic colitis. This is when blood flow to your colon slows down or stops. The lack of oxygen causes damage to your intestine. The blockage can happen slowly over time, such as when cholesterol builds up in your arteries.

Or it can happen all of a sudden from a blood clot or from a serious drop in your blood pressure. It can lead to bloody diarrhea. It usually also comes with abdominal pain that can be serious. The pain usually worsens when you eat.

Bacterial infections. Bloody diarrhea from IBD can last for a while if you don’t treat it. If it’s from a bacterial infection, it doesn’t usually last more than 2 weeks. It doesn’t come back after it gets better unless you catch the same infection again. Bacterial infections that can cause bloody diarrhea include E. coli., salmonella, shigella, and campylobacter.

Diverticular disease. Diverticula are small pouches that project from the colon wall. Usually diverticula don’t cause problems, but sometimes they can bleed or become infected.

Anal fissure. This is a small cut or tear in the tissue lining the anus similar to the cracks that occur in chapped lips or a paper cut. Fissures are often caused by passing a large, hard stool and can be painful.

Colitis. This is inflammation of the colon.

Angiodysplasia. This is a condition in which fragile, abnormal blood vessels lead to bleeding.

Peptic ulcer. This is an open sore in the lining of the stomach or duodenum, the upper end of the small intestine. Many peptic ulcers are caused by infection with a bacterium called Helicobacter pylori (H. pylori). Long-term use or high doses of anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen can also cause ulcers.

Polyps or cancer. Polyps are benign growths that can grow, bleed, and could become cancerous. Colorectal cancer is the fourth most common cancer in the U.S. It often causes bleeding that is not noticeable with the naked eye.

Esophageal problems. Varicose veins of the esophagus or tears in the esophagus can lead to severe blood loss.

Blood in Stool Diagnosis

It is important to have a doctor evaluate any bleeding in the stool. Any details you can give about the bleeding will help your doctor locate the site of bleeding. For example, a black, tarry stool is likely an ulcer or other problem in the upper part of the digestive tract.

Bright red blood or maroon-colored stools usually indicate a problem in the lower part of the digestive tract such as hemorrhoids or diverticulitis.

Written by Mary Anne Dunkin

Medically Reviewed by Carmelita Swiner, MD on January 04, 2023

Source: www.webmd.com