Blood in Stools: What Tests are There?

For many people, finding blood in stools can be a scary experience. While blood in the stools can indicate a serious medical problem, it’s not the case all the time. In some instances, blood in stools can be caused by a bleeding in the digestive tract. At times, the blood is so small that a fecal occult test is needed to detect it

Essentially, a fecal occult test is done to check for hidden blood found in the stool. In other instances, the blood can be visible on the toilet and the toilet tissue after your bowel movement. Bleeding that can occur way high in the digestive tract. This makes the stool appear tarry and black.

Blood in the Stool: Possible Causes


Blood in the stool can be attributed to some of the following:

  • Esophageal problems. Any tear in the esophagus or varicose veins in the varicose veins can result in severe blood loss.
  • Cancer or polyps. Colorectal cancer is quite common. However, it can sometimes cause bleeding that is not noticeable to the naked eye. On the other hand, polyps are growths that are benign that can grow and bleed. Unfortunately, it can also become cancerous.
  • Peptic ulcers. If there is an open sore in the duodenum or the stomach lining, peptic ulcer can occur. Most peptic ulcers are caused by Helicobacter pylori infection. High doses or long-term use of anti-inflammatory drugs such as naproxen, aspirin, and ibuprofen can also lead to ulcers.
  • Angiodysplasia. This condition develops when abnormal and fragile blood vessels bleed.
  • Colitis. This is also known as colon inflammation. Some of the most common causes of colitis include inflammatory bowel disease or infections.
  • Anal fissure. A small tear or cut in the tissue that lines that anus is known as anal fissure. These are caused by passing hard and large stools. 
  • Diverticular disease. The small pouches that project from the colon wall are known as diverticula. While diverticula won’t always cause any problems, they can also become infected and bleed.

Blood in Stool Tests

Some of the tests that can determine the possible cause of blood in stools include:

  • Colonoscopy. During colonoscopy, a scope is inserted through the rectum in order to view the colon. Collecting tissue samples for biopsy can also be done during the procedure.
  • Nasogastric lavage. This test can help determine if bleeding is in the lower or upper digestive tract. The procedure can involve the removal of stomach content using a tube that is inserted in the stomach. 
  • Esophagogastroduodenoscopy (EGD). An endoscope is inserted through the mouth and it passes through the esophagus down to the stomach and the duodenum. Endoscopy is used to determine the cause of the bleeding and to collect tissue for biopsy.
  • Radionuclide scanning. This procedure involves injecting the vein with a small amount of radioactive material. A special camera is used to see the blood flow images in the digestive tract. This is also done to determine the source of the bleeding. 
  • Laparotomy. This surgical procedure involves opening and examining the abdomen. This may be the recommended option if all the other tests have not been able to determine the cause of the bleeding.

In some instances, people might be unaware of the bleeding and will not notice any symptoms. On the other hand, blood in the stools can be accompanied by other symptoms including vomiting, abdominal pain, breathing difficulties, weakness, fainting, palpitations, diarrhea, and weight loss.