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Seeing a Blood Clot in Your Stool? Here’s What It Could Mean

January 7, 2026


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What Do Blood Clots in Stool Look Like? Understanding the Clues

Before a doctor can make a diagnosis, they will ask detailed questions about what you saw. The color and consistency of the blood and clots provide crucial clues about where the bleeding might be located within your long and complex GI tract.

Bright Red Blood Clots (Hematochezia)

If you see bright red blood clots in stool, this is a condition known as hematochezia. This vibrant color typically indicates that the bleeding is happening in the lower part of your GI tract—most likely the colon or rectum. Because the blood is fresh and hasn’t had time to be broken down by digestive enzymes, it retains its bright red appearance. The presence of clots suggests the bleeding might be more significant or faster than a simple surface-level tear.

Dark Red or Maroon Blood Clots

When you find dark red or maroon-colored blood and clots, it generally suggests the bleeding is occurring higher up in the GI tract than the rectum. This could be in the right side of the colon or the small intestine. The blood has traveled a longer distance, giving it time to mix with stool and begin to deoxygenate, which results in a darker hue. Seeing dark red blood in stool is a significant finding that requires a thorough medical investigation.

Black or Tarry Stools (Melena)

While not a clot in the traditional sense, black, sticky, tar-like stools are a sign of digested blood. This condition, called melena, points to bleeding in the upper GI tract, such as the esophagus, stomach, or the first part of the small intestine (duodenum). By the time the blood makes its way through the entire digestive system, digestive enzymes have turned it black. Conditions like peptic ulcer bleeding are a frequent cause of melena.

Blood with Mucus

Sometimes, you may notice mucus and blood in stool. Mucus is a natural lubricant in the intestines, but an excess amount, especially when mixed with blood, often signals inflammation. This combination is a common hallmark of conditions like inflammatory bowel disease or certain infections.


Should I see a doctor for a blood clot in stool?

Yes. Seeing a doctor is wise if you notice blood clots in your stool because it usually means internal bleeding from somewhere in your digestive tract, ranging from minor issues to serious conditions that need treatment. Immediate care is important if bleeding is heavy or comes with pain, dizziness, or fever.

What Causes Blood Clots in Stool? A Breakdown of Potential Sources

Understanding what causes blood clots in stool involves looking at a wide spectrum of conditions. Here are some of the most common culprits, ranging from frequently seen issues to more serious diseases.

1. Hemorrhoids and Anal Fissures

These are two of the most common causes of rectal bleeding with clots, especially bright red blood. * Hemorrhoids: These are swollen veins in your rectum or anus. Straining during bowel movements can cause them to bleed. Sometimes, a blood clot can form inside an external hemorrhoid, creating a painful lump known as a thrombosed hemorrhoids blood clot. * Anal Fissures: These are small tears in the lining of the anus, often caused by passing hard stools. They can be painful and cause bright red bleeding.

While common, you should never assume your bleeding is “just hemorrhoids” without a proper diagnosis.

2. Diverticular Disease

Diverticulosis is a condition where small pouches, called diverticula, form in the walls of the colon. According to the National Institute of Diabetes and Digestive and Kidney Diseases, this condition is common, especially in adults over 60 source. These pouches can sometimes bleed, a condition known as diverticular bleeding. This can cause a large amount of painless bleeding, often producing both bright and dark red blood in stool with clots.

3. Inflammatory Bowel Disease (IBD)

IBD is a term for two chronic conditions that cause inflammation of the GI tract: Crohn’s disease and ulcerative colitis. * Ulcerative Colitis (UC): This condition causes inflammation and ulcers in the lining of the colon and rectum. Bloody diarrhea, often with mucus and clots, is a hallmark symptom. * Crohn’s Disease: This can affect any part of the GI tract. When it affects the colon, inflammatory bowel disease (IBD) blood in stool is a common symptom due to deep ulcerations in the intestinal wall.

4. Infectious Colitis and Gastroenteritis

Bacterial infections can wreak havoc on your colon, leading to inflammation, diarrhea, and bleeding. Organisms like Salmonella, Campylobacter, Shigella, and E. coli O157:H7 can cause severe inflammation that damages the intestinal lining. Key infectious colitis symptoms include sudden-onset bloody diarrhea, abdominal cramps, and fever.

5. Ischemic Colitis

This condition occurs when blood flow to a part of the colon is reduced, often due to narrowed arteries or a blood clot. This lack of oxygenated blood injures the cells of the colon lining, leading to pain and bloody stools. Ischemic colitis is more common in older adults and often presents with sudden abdominal cramping followed by the urgent passage of blood and clots.

6. Peptic Ulcers

These are open sores that develop on the inside lining of your stomach (gastric ulcers) or the upper portion of your small intestine (duodenal ulcers). While peptic ulcer bleeding typically causes black, tarry stools (melena), severe and rapid bleeding can sometimes result in maroon-colored stools if the blood moves through the GI tract quickly.

7. Colon Polyps and Colorectal Cancer

This is often the most significant concern when people see blood in their stool. * Colon Polyps: These are small growths on the lining of the colon. While often benign, they can bleed, and some types can develop into cancer over time. * Colorectal Cancer: As tumors grow in the colon or rectum, they can bleed. Bleeding is one of the key colon cancer symptoms, which is why it should never be ignored. The American Cancer Society highlights changes in bowel habits and blood in the stool as critical warning signs to discuss with a doctor source. Finding and removing polyps through screening colonoscopies is the most effective way to prevent colorectal cancer.

A Quick Note on “False Alarms”: Certain foods and medications can change the color of your stool, making it look like there’s blood. Beets and red food coloring can turn stool reddish, while iron supplements and bismuth-containing medicines (like Pepto-Bismol) can turn it black. However, these do not cause actual blood clots. If you see what looks like a clot, it’s very unlikely to be from food. When in doubt, always get it checked out.


When to See a Doctor (And When It’s an Emergency)

Let’s be perfectly clear: any time you see a blood clot in stool, you should schedule an appointment with your doctor. It is not a symptom to watch and wait on. Figuring out when to see a doctor for blood in stool is simple: always.

However, certain accompanying symptoms signal a medical emergency that requires an immediate trip to the emergency room.

Seek Immediate Medical Care If You Experience:

  • Heavy or continuous rectal bleeding or passing numerous large clots.
  • Severe abdominal pain, cramping, or tenderness.
  • Dizziness, lightheadedness, or fainting, which could be signs of significant blood loss.
  • A rapid or irregular heartbeat.
  • High fever accompanied by bloody diarrhea.
  • Vomiting blood or a substance that looks like coffee grounds.
  • Pale, cold, or clammy skin and shortness of breath.

These symptoms could indicate severe internal bleeding, a serious infection, or shock, and they require urgent medical intervention.


Diagnosis and Treatment: How Your Doctor Will Investigate

When you see your doctor for rectal bleeding with clots, they will begin a systematic process to pinpoint the cause.

The Diagnostic Process

  1. Medical History and Physical Exam: Your doctor will ask about your symptoms in detail, your diet, medications, and family history. A physical exam, which may include a digital rectal exam to check for hemorrhoids or other issues near the anus, will be performed.
  2. Lab Tests: Blood tests can check for anemia (low red blood cell count) from blood loss and signs of infection. A stool sample may be tested for hidden (occult) blood, bacteria, or other infectious agents.
  3. Endoscopic Procedures: To see what’s happening inside your GI tract, your doctor will likely recommend an endoscopic procedure.
    • Colonoscopy: This is the gold standard for examining the entire colon. A thin, flexible tube with a camera is used to look for polyps, tumors, diverticula, or sources of inflammation. Polyps can often be removed during the procedure.
    • Upper Endoscopy (EGD): If the cause is suspected to be in the upper GI tract (due to melena), this procedure is used to examine the esophagus, stomach, and duodenum.

Treatment Is Tied to the Cause

Treatment is entirely dependent on the diagnosis. There is no single “cure” for a blood clot in stool because it’s a symptom, not a disease. * Hemorrhoids/Fissures: Often managed with lifestyle changes like increased fiber and water, and topical medications. * IBD or Infections: Treated with medications to reduce inflammation or antibiotics to clear the infection. * Diverticular Bleeding: Often stops on its own, but severe cases may require intervention during a colonoscopy or surgery. * Polyps and Cancer: Polyps are removed during a colonoscopy. A cancer diagnosis requires a dedicated team and a treatment plan that may include surgery, chemotherapy, and/or radiation.


Your Health Is Your Priority

Seeing a blood clot in stool is rightfully unsettling, but it’s also a powerful signal from your body that demands attention. Remember the key takeaways: the color of the blood offers clues, the causes are diverse ranging from the common to the critical and a medical evaluation is non negotiable.

Resist the urge to self diagnose or hope it goes away on its own. The peace of mind that comes from a definitive diagnosis is invaluable. Schedule an appointment with your healthcare provider to discuss your symptoms. Taking this step is the most important thing you can do for your health and well being.

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