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Published on: 2/24/2026
Blood in stool can come from hemorrhoids or anal fissures, diverticular bleeding, inflammatory bowel disease, colon polyps or cancer, or bleeding higher in the digestive tract, with bright red blood suggesting a lower source and black tarry stool pointing to the stomach or small intestine; heavy or ongoing bleeding, black stool with lightheadedness, severe pain, dizziness, or weakness need urgent care.
Medically approved steps include not ignoring symptoms, tracking color and amount, reviewing bleeding risk medicines, using a symptom checker, and seeing a doctor for persistent or recurrent bleeding, age over 45, anemia, weight loss, or abdominal pain, with tests like stool studies, colonoscopy, or endoscopy to identify and treat the cause; there are several factors to consider, so see the complete details below.
Seeing blood in your stool can be alarming. It's not something to ignore — but it's also not always a medical emergency. In many cases, the cause is treatable and not life-threatening. The key is understanding why it may be happening and knowing when to take action.
This guide explains the most common causes of blood in stool, what different types of bleeding can mean, and medically approved next steps.
Not all blood in stool looks the same. The appearance can give important clues about where the bleeding is happening in your digestive tract.
You might notice:
The color matters because it suggests where the bleeding may be coming from:
There are several medically recognized causes of gastrointestinal bleeding. Some are mild. Others require prompt medical care.
Hemorrhoids are swollen veins in the rectum or anus. They are one of the most common reasons for bright red blood in stool.
You may notice:
Hemorrhoids are often linked to:
While uncomfortable, they are usually not dangerous.
An anal fissure is a small tear in the lining of the anus.
Symptoms often include:
Fissures are commonly caused by hard stools or chronic constipation.
Diverticula are small pouches that can form in the colon wall. If one bleeds, it can cause sudden, noticeable blood in stool — sometimes a significant amount.
This type of bleeding:
Conditions like Crohn's disease and ulcerative colitis cause chronic inflammation in the digestive tract.
Symptoms may include:
IBD requires ongoing medical management.
Polyps are growths in the colon that can sometimes bleed. Some polyps can become cancerous over time.
Colorectal cancer may cause:
Not every case of blood in stool means cancer. However, persistent or unexplained bleeding must be evaluated — especially if you are over 45 or have a family history of colorectal cancer.
If the bleeding happens in the stomach or small intestine, stool may appear black and tarry.
Causes can include:
Black stool should always be evaluated by a healthcare professional.
Seek immediate medical attention if you experience:
These symptoms may indicate significant blood loss and require urgent care.
If you notice blood in your stool, here are responsible next steps.
Occasional small amounts of bright red blood from hemorrhoids may not be urgent. However, recurring bleeding should always be evaluated.
Make note of:
This information helps doctors identify the cause faster.
Certain medications increase bleeding risk, including:
Do not stop prescribed medication without speaking to a doctor — but mention it during your visit.
If you're unsure what might be causing your symptoms, using a free AI-powered blood in stool symptom checker can help you understand possible causes and determine how urgently you should seek care.
It does not replace medical evaluation, but it can guide your next steps with personalized insights based on your specific symptoms.
Any of the following situations require medical evaluation:
Doctors may recommend:
These tests help identify the source of bleeding and guide treatment.
Treatment depends entirely on the cause.
Examples include:
Early detection significantly improves outcomes, particularly for colorectal cancer.
Yes — especially if constipation or hemorrhoids are involved.
Helpful habits include:
However, lifestyle changes alone are not enough if the bleeding source is internal or more serious.
Sometimes blood in stool isn't visible. Routine screening tests can detect microscopic bleeding.
This is why colorectal cancer screening is recommended starting at age 45 for average-risk adults.
Even if you feel fine, screening saves lives.
Blood in your stool is a sign that something in your digestive tract is bleeding. The cause may be minor — like hemorrhoids — or more serious, such as inflammatory bowel disease or colorectal cancer.
Here's what matters most:
If you are unsure what your symptoms mean, use Ubie's free blood in stool symptom checker to better understand possible causes and receive guidance on your next steps — then follow up appropriately.
Most importantly, speak to a doctor about any bleeding that is ongoing, severe, or accompanied by concerning symptoms. Gastrointestinal bleeding can sometimes signal life-threatening conditions, and timely evaluation makes a real difference.
Your body is giving you information. Listen to it — and act wisely.
(References)
* Laine L, Barkun AN, Ofman JJ, Laine M, Martel M, Leontiadis GI. Upper and Lower Gastrointestinal Bleeding. N Engl J Med. 2021 Sep 16;385(12):1111-1120. doi: 10.1056/NEJMcp2102921. PMID: 34525049.
* Strate LL, Gralnek IM, Siddique SM, Baradarian R, Falck-Ytter Y, Kamboj AK. AGA Clinical Practice Guideline on the Management of Lower Gastrointestinal Bleeding. Gastroenterology. 2023 Sep;165(3):617-639. doi: 10.1053/j.gastro.2023.05.045. PMID: 37374026.
* Gralnek IM, Barkun AN, Gerson LB, Laine L. Gastrointestinal bleeding. Lancet. 2017 Aug 26;390(10098):991-1001. doi: 10.1016/S0140-6736(17)31481-X. PMID: 28847427.
* Liao X, Dong T, Li S, Hu M, Hou X, Li Y, Wang H. Evaluation and Management of Obscure Gastrointestinal Bleeding. Clin Transl Gastroenterol. 2023 Jun 13;14(6):e00595. doi: 10.14309/ctg.0000000000000595. PMID: 37311197.
* Cirocco L, Leef JA. Gastrointestinal Bleeding: A Practical Approach. Semin Intervent Radiol. 2020 Dec;37(5):548-557. doi: 10.1055/s-0040-1718820. Epub 2020 Dec 20. PMID: 33281358.
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