Blood in your poop is common, and in most cases it comes from a minor, treatable condition like hemorrhoids or a small tear in the skin around the anus. In one clinical study of 120 patients with rectal bleeding, hemorrhoids accounted for nearly 52% of cases and anal fissures for another 21%. That said, the color, amount, and accompanying symptoms all matter, because blood in your stool can occasionally signal something more serious that needs prompt evaluation.
What the Color of the Blood Tells You
The color is your first useful clue. Bright red blood, whether on the toilet paper, coating the stool, or dripping into the bowl, typically comes from the lower part of your digestive tract: the colon, rectum, or anus. Doctors call this hematochezia, and it’s the type most people notice.
Dark, tarry, sticky stool with a distinctive foul smell usually points to bleeding higher up, in the stomach or upper small intestine. Blood that travels through the full length of your digestive system gets broken down along the way, turning black. If your stool looks like this and you haven’t recently taken iron supplements, bismuth-based antacids, or eaten black licorice or blueberries, it’s worth getting checked quickly. Maroon-colored stool falls somewhere in between, often suggesting bleeding in the upper colon or small bowel.
Foods and Medications That Mimic Blood
Before you worry, consider what you’ve eaten or taken recently. Beets and foods with red coloring can make stool appear reddish and look alarmingly like blood. On the darker side, iron pills, activated charcoal, bismuth medications, blueberries, and black licorice can all turn stool black without any bleeding at all. If you recently consumed any of these, wait a day or two and see if your stool returns to normal.
Hemorrhoids: The Most Common Cause
Hemorrhoids are swollen blood vessels in the rectum or anus, and they’re the single most frequent reason people see blood in their stool. Internal hemorrhoids, which sit inside the rectum, typically cause painless bleeding. You might notice bright red blood on the toilet paper or see it drip into the bowl, but feel nothing unusual. External hemorrhoids, closer to the outside, are more likely to cause itching, swelling, or mild discomfort.
Straining during bowel movements, sitting on the toilet for long periods, chronic constipation, and pregnancy all increase your risk. Most hemorrhoids improve with more fiber, more water, and less time straining on the toilet.
Anal Fissures: When It Hurts Too
If you see blood and feel a sharp, stinging pain during or after a bowel movement, an anal fissure is a likely culprit. Fissures are small tears in the lining of the anus, usually caused by passing a large or hard stool. The pain can linger as itching or burning that doesn’t go away between bowel movements, which is a key way to tell them apart from hemorrhoids. Most fissures heal on their own within a few weeks with softer stools and warm baths, though some become chronic and need further treatment.
Inflammatory Bowel Disease
Bloody diarrhea, especially with mucus or pus, points toward inflammatory bowel disease. Ulcerative colitis, for example, often starts with mild symptoms like slightly bloody diarrhea and four or fewer loose stools a day. As it progresses, bowel movements become more frequent and may contain visible blood, mucus, or pus. Crohn’s disease can cause similar symptoms depending on which part of the digestive tract is inflamed.
The pattern matters here. Hemorrhoids and fissures cause bleeding that comes and goes, usually tied to individual bowel movements. Inflammatory bowel disease tends to cause persistent or worsening symptoms over weeks, often accompanied by cramping, urgency, fatigue, or weight loss.
Medications That Raise Your Risk
Certain medications make your digestive tract more vulnerable to bleeding. Regular use of anti-inflammatory painkillers like ibuprofen or naproxen roughly doubles the risk of bleeding in the colon. The risk climbs even higher if you’re also taking a blood thinner. One meta-analysis found that people taking both a blood thinner and an anti-inflammatory painkiller had about 2.5 to 3 times the risk of gastrointestinal bleeding compared to people on neither. If you take these medications regularly and notice blood in your stool, that combination is important to mention to your doctor.
How Likely Is It to Be Cancer?
This is the question behind the question for most people searching this topic. The honest answer: it’s possible but not probable. Among adults 45 and older who saw a doctor specifically for new rectal bleeding, about 5.7% were diagnosed with colorectal cancer. The risk rises with age. In one study, no patients between 45 and 54 with rectal bleeding turned out to have cancer, compared to about 9.5% of those between 65 and 74.
Colorectal cancer is more likely to cause persistent changes in bowel habits, unexplained weight loss, a feeling that your bowel doesn’t empty completely, or blood mixed into the stool rather than sitting on top of it. None of these signs are definitive on their own, which is why routine screening matters. The current recommendation is that most adults should begin colorectal cancer screening at age 45, regardless of symptoms.
What to Expect at the Doctor
Your doctor will start by asking about the color, frequency, and amount of bleeding, along with any other symptoms. A physical exam often includes a visual inspection and sometimes a brief internal exam of the lower rectum. For hemorrhoids specifically, the best way to confirm the diagnosis is direct visualization with a small scope while you bear down.
If there’s any concern about a cause beyond hemorrhoids or fissures, the next step is usually a colonoscopy. This lets a gastroenterologist examine the entire colon, identify the source of bleeding, and in many cases treat it during the same procedure. You’ll need to complete a bowel preparation beforehand, and you’ll be sedated during the exam itself. Most people go home the same day.
Signs That Need Emergency Attention
A small amount of bright red blood on the toilet paper after a hard bowel movement can usually wait for a regular appointment. But heavy bleeding or bleeding combined with any of the following needs emergency care:
- Dizziness or lightheadedness when standing up
- Rapid, shallow breathing
- Fainting or confusion
- Cold, clammy, or pale skin
- Nausea
- Very low urine output
- Blurred vision
These are signs your body is losing enough blood to affect circulation. They require immediate evaluation, not a wait-and-see approach.