Why Is There Blood in My Poop? Causes & When It’s Serious

Key takeaways:

• Blood in stool can range from mild, temporary causes to serious medical conditions requiring immediate attention.
• The color and amount of blood, along with accompanying symptoms, help determine the underlying cause.
• While common and often treatable, a healthcare provider should evaluate any unexplained blood in the stool.

Finding blood in your stool is often alarming. This symptom, known medically as hematochezia (bright red blood) or melena (dark, tarry stools), affects many people at some point in their lives.

While blood in your poop can sometimes indicate a serious condition, it often has treatable causes. In many cases, simple adjustments to your diet or routine may stop your symptoms. This article will explore the various reasons for blood in stool, help you understand what's normal, and guide you on when to contact a healthcare provider.

Is blood in poop normal?

Blood in stool is not necessarily normal, but it is common. The presence of blood can range from barely noticeable pink-tinged toilet paper to clearly visible red streaks (hematochezia) or dark, tarry stools (melena.)

While some causes may be minor and self-limiting, unexplained bleeding in your stool should be evaluated by your doctor.

Causes of having blood in poop

Gastrointestinal (GI) bleeding is a sign of something happening in the digestive system. You will have overt (easy to see) or occult (difficult to see) signs of GI bleeding.

The source could be in the upper or lower part of your GI system. “Upper” refers to body parts like the esophagus and stomach. “Lower” typically refers to the colon, rectum, and anus. The location and nature of bleeding often provide clues about the cause.

Upper GI bleeding

Bleeding in the stomach or small intestine may be associated with:

• Dark, tarry stools (melena)
• Upper abdominal pain
• Ulcers or medications
• Vomiting (especially vomit that looks like coffee grounds)

Peptic ulcers

Peptic ulcers are open sores that develop on the stomach's inner lining and the small intestine's upper portion.

Ulcers develop when stomach acid damages the stomach or small intestine’s protective layer, leading to erosion of the underlying tissue. H. pylori bacteria and long-term use of pain medications often cause these ulcers.

Polyps and colorectal cancer

Polyps are abnormal tissue growths that stick out from the lining of the colon or rectum. They are more common in adults over 45.

While most polyps are benign (non-cancerous), some can develop into colorectal cancer over time. This transformation typically takes several years, so regular screening is crucial.

Polyps have the following characteristics:

• Abnormal tissue growths
• Possibility to develop into cancer if untreated
• Possibility to cause hidden or visible bleeding
• Often discovered during routine screenings

Colon cancer, which is more common in adults over 50, can cause:

• Blood in the stool (either bright red or dark)
• Changes in bowel habits
• Unexplained weight loss
• Fatigue and weakness
• Anemia

Diverticular disease

Diverticular disease develops when small, bulging pouches (diverticula) form in the digestive tract, usually in the colon.

Diverticula form when weak spots in the wall of the gut balloon outward, creating small sacs that can become inflamed or bleed. The condition is more common among older adults and those who eat less fiber.

Inflammatory bowel disease (IBD)

Crohn's disease and ulcerative colitis, which are two common types of IBD, can cause:

• Chronic inflammation of the digestive tract
• Blood mixed with mucus in stool
• Abdominal pain and cramping
• Diarrhea and weight loss

Gastroenteritis

Gastroenteritis, or stomach flu, is an inflammation of the stomach and intestines, typically caused by viral or bacterial infections. This condition can damage the lining of the digestive tract, leading to inflammation and bleeding.

Gastroenteritis can result in bloody diarrhea and is often accompanied by nausea and vomiting. This infection usually resolves within two weeks. It may be related to food poisoning.

Ischemic colitis

Ischemic colitis occurs when blood flow to part of the large intestine (colon) is reduced.

This reduction in blood flow causes tissue damage or cell death with inflammation in the affected area of the colon. Ischemic colitis can develop gradually or suddenly and often causes bloody diarrhea. You may also experience abdominal pain, which typically worsens after you eat.

Hemorrhoids (piles)

Hemorrhoids are swollen blood vessels that develop in the lower rectum and anus. They form when increased pressure causes them to swell. This condition affects nearly 75% of adults at some point and is the most common cause of bloody stool.

Straining during bowel movements and heavy lifting are two common causes of hemorrhoids. They may cause itching and discomfort. Hemorrhoids usually result in small amounts of bright red blood on toilet paper.

Anal fissures

An anal fissure is a small tear in the thin, moist tissue (mucosa) that lines the anus. Think of it as a paper cut in the anal tissue.

These tears typically occur when passing large or hard stools. Anal fissures may cause bright red bleeding and rectal pain.

Sexually transmitted infections (STIs)

Infections transmitted through sexual contact can cause inflammation and bleeding.

These infections can affect the delicate tissues of the anus and rectum, leading to various complications if left untreated. Common culprits include gonorrhea, chlamydia, and herpes. You may notice other symptoms along with bloody stool.

Medication-related bleeding

Certain medications, particularly blood thinners and anti-inflammatory drugs, can increase the risk of bleeding in the digestive tract.

These medications sometimes affect the protective lining of the digestive system. Warfarin and Aspirin are two such medications.

Endometriosis

Endometriosis is a condition where tissue similar to the lining of the uterus grows outside the uterus.

When this tissue develops in or around the bowel, it can cause bleeding and other digestive symptoms, particularly during menstruation.

Read our guides on different types of stool and stool colors for more.

Health risks associated with bloody stool

Bloody stool can indicate various health conditions ranging from minor concerns to medical emergencies.

You can make informed decisions about seeking medical care by understanding these risks. Below are some significant health risks associated with bloody stool, listed from most urgent to least urgent conditions:

Severe blood loss and anemia

This condition is marked by rapid blood loss that requires emergency treatment. It occurs when you have a low red blood cell count.

Emergency signs include feeling faint or weak, rapid heartbeat, confusion, or passing large amounts of blood. You may also have pale skin or experience shortness of breath. If you experience these emergency signs, seek immediate medical care.

Inflammatory bowel disease complications

Chronic inflammation can lead to:

• Narrowing of intestines
• Bowel obstruction
• Increased risk of colorectal cancer
• Malnutrition
• Fistulas (abnormal connections between organs)
• Joint problems and skin conditions

Other signs of IBD include chronic diarrhea, abdominal pain, weight loss, and fatigue. If you have these symptoms, seek medical care promptly.

Diverticular disease complications

Untreated diverticulitis can result in:

• Abscess formation
• Perforation of the bowel wall
• Peritonitis (infection in the abdominal cavity)
• Bowel obstruction
• Changes in bowel habits
• Formation of fistulas
• Severe bleeding episodes

Warning signs that should prompt you to seek emergency care include severe or worsening abdominal pain, high fever, and significant blood loss.

Upper GI bleeding complications

Bleeding from the upper digestive tract can cause:

• Severe blood loss
• Aspiration of blood (inhaling blood into your airway)
• Shock
• Infection
• Organ failure (in severe cases)
• Recurrent bleeding if the underlying cause isn't treated

Warning signs include black, tarry stools, vomiting blood, and burning pain in the upper abdomen.

When to see a doctor about bloody poop

While many causes of bloody stool are minor, the potential risks of delayed treatment make medical evaluation essential. Never assume the bleeding is from a benign cause without a proper medical assessment.

Schedule an appointment with your doctor if you notice:

• Small amounts of bright red blood
• Blood that appears only occasionally
• Mild symptoms that don't improve after a few days
• Any unexplained bleeding, even if minor

Seek immediate medical attention if you experience:

• Large amounts of blood
• Black, tarry stools
• Vomiting blood
• Vomit that looks like coffee grounds
• Severe abdominal pain
• Dizziness or fainting
• Fever above 101°F (38.3°C)
• Confusion
• Cold or clammy skin

Questions to ask your doctor about blood in your poop

• What will you do to determine the cause of my bloody poop?
• Could anemia be the cause of my bloody poop?
• Are there any lifestyle or dietary changes I should make?
• What other symptoms should I look out for?

How to stop or treat bloody poop

The following actions may help stop your bloody stools:

• See your doctor for any unexplained bleeding
• Complete recommended cancer screenings
• Follow your prescribed treatment plans
• Maintain a healthy, high-fiber diet
• Stay hydrated
• Exercise regularly
• Avoid straining during bowel movements

How to prevent bloody poop

If you have already experienced bloody stools, here are some tips to help you prevent them in the future:

• Keep a diary of your symptoms
• Follow up with your recommended screenings
• Report any new symptoms to your doctor
• Get regular check-ups
• Follow preventive care guidelines
• Monitor for recurring symptoms

Frequently asked questions: blood in poop

If you have experienced blood in your poop, you will naturally have questions about your symptoms. Here are some of the most frequently asked questions.

How much blood in stool or poop is normal?

No amount of blood in stool is technically "normal," but the amount can help indicate the severity of the situation.

Trace amounts (a few drops):

• Are often associated with minor issues like hemorrhoids or anal fissures
• May appear as red streaks on toilet paper
• Are usually not urgent if occasional and accompanied by no other symptoms

Small amounts (a teaspoon or less):

• Should be evaluated by a healthcare provider
• May indicate treatable conditions
• Should prompt you to look out for other symptoms

Large amounts (more than a tablespoon) require immediate medical attention.

Is bright red blood in poop serious?

Bright red blood in poop can occasionally lead to dangerous blood loss. Although the cause may be minor, bright red blood in stools may indicate a serious condition.

If you don’t know the cause of your bloody stools, you should seek medical care.

What foods or drinks cause bloody poop?

While foods don't typically cause actual bleeding, some can create the appearance of blood or make existing bleeding worse.

Foods that may make your poop look like blood include:

• Beets
• Red dragon fruit
• Red food coloring
• Red Jell-O
• Tomato juice or soup
• Red wine

Foods that might worsen existing bleeding include:

• Blood-thinning foods:
• Garlic
• Ginger
• Turmeric
• Fish oil supplements

Final thoughts about blood in poop

While blood in stool is a common occurrence that often has benign causes, it should never be ignored. Proper medical evaluation can identify the underlying cause and ensure appropriate treatment. Early detection of serious conditions leads to better outcomes, so don't hesitate to discuss this symptom with your healthcare provider.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Lane Thaut, DO.

Sources

Bruner, Lia Pierson et al. “Inflammatory Bowel Disease.” Primary care vol. 50,3 (2023): 411-427. doi:10.1016/j.pop.2023.03.009

Costable, Nicholas J, and David A Greenwald. “Upper Gastrointestinal Bleeding.” Clinics in Geriatric Medicine vol. 37,1 (2021): 155-172. doi:10.1016/j.cger.2020.09.001

Dykstra, Mark A, and W Donald Buie. “Anal fissures.” CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne vol. 191,26 (2019): E737. doi:10.1503/cmaj.190074

Domas, Erik, et al. “Current Management of Diverticulitis.” The Surgical Clinics of North America vol. 104,3 (2024): 529-543. doi:10.1016/j.suc.2023.12.001

Drezdzon, Melissa K, and Kent J Peterson. “Evaluation and Management of Lower GI Bleeding.” Diseases of the colon and rectum vol. 65,6 (2022): 785-788. doi:10.1097/DCR.0000000000002461

Flynn, Thomas G et al. “Viral gastroenteritis.” Lancet (London, England) vol. 403,10429 (2024): 862-876. doi:10.1016/S0140-6736(23)02037-8

Piscopo, Naomi, and Pierre Ellul. “Diverticular Disease: A Review on Pathophysiology and Recent Evidence.” The Ulster Medical Journal vol. 89,2 (2020): 83-88.

Sabry, Ahmed O. and Tanuj Sood. “Rectal Bleeding.” StatPearls, StatPearls Publishing, 31 July 2023.