If you have blood clots in your stool, this is commonly a sign of bleeding from the large intestine (colon). It’s also a signal that you should get medical attention immediately.

There are various medical conditions that can result in bleeding from the colon.

Diverticular bleeding

Pouches (diverticula) can develop on the wall of the large intestine. When these pouches bleed, it’s called diverticular bleeding. Diverticular bleeding can cause a large amount of blood in your stool.

The blood in your stool may be bright or dark red clots. Diverticular bleeding often stops on its own and, in most cases, it’s not accompanied by pain.

If diverticular bleeding does not stop on its own, surgery may be required. Treatment may also include blood transfusions and intravenous fluids.

Infectious colitis

Infectious colitis is an inflammation of the large intestine. It’s typically caused by infection from viruses, bacteria, parasites, or fungus. This inflammation is often associated with food poisoning.

Symptoms might include:

Treatment of infectious colitis might include:

Ischemic colitis

When blood flow to the colon is reduced — commonly caused by narrowed or blocked arteries — the decreased flow of blood doesn’t provide enough oxygen to your digestive tract. This condition is called ischemic colitis. It can damage your large intestine and cause pain.

Symptoms might include:

  • abdominal pain or cramping
  • nausea
  • passage of blood clots (maroon-colored stool)
  • passage of blood without stool
  • passage of blood with your stool
  • feeling of immediate need to move your bowels (tenesmus)
  • diarrhea

In mild cases of ischemic colitis, the symptoms might virtually disappear in a few days. For treatment, your doctor might recommend:

  • antibiotics for infections
  • intravenous fluids for dehydration
  • treatment for the underlying condition that triggered it

Inflammatory bowel disease

Inflammatory bowel disease (IBD) represents a group of intestinal disorders. These include gastrointestinal tract inflammation such as Crohn’s disease and ulcerative colitis. Symptoms might include:

  • diarrhea
  • abdominal pain or cramping
  • fatigue
  • fever
  • passage of blood clots (maroon colored stool)
  • passage of blood with your stool
  • reduced appetite
  • weight loss

Treatment for IBD might include:

  • antibiotics
  • anti-inflammatory drugs
  • immune system suppressors
  • pain relievers
  • antidiarrheal medication
  • surgery

Other possible causes

If there’s blood, there may be blood clots. Some diseases and conditions that could cause blood in your stool include:

Unexplained bleeding is always a reason to get a diagnosis from your doctor. If you have blood clots in your stool, it’s an indication of significant bleeding. You should see your doctor as soon as possible.

You should get emergency medical treatment if you’re also experiencing additional symptoms including:

  • vomiting blood
  • severe or increasing abdominal pain
  • high fever
  • dizziness or fainting
  • rapid pulse

The appearance of blood clots in your stool is often a sign of bleeding from the colon. There are a number of potential causes including diverticular bleeding, infectious colitis, and inflammatory bowel disease.

If you’re bleeding or see signs of bleeding — such as a blood clot — make an appointment to see your doctor for a diagnosis. If your doctor is booked, consider going to an emergency medical facility.