Blood in your poop is not always a sign of something serious, but it should never be completely ignored. In most cases, the cause is something common and treatable like hemorrhoids or a small tear near the anus. That said, the color of the blood, how much there is, and whether you have other symptoms all matter when figuring out what’s going on.
What the Color of the Blood Tells You
The color is one of the biggest clues to where the bleeding is coming from. Bright red blood typically starts in the lower part of the digestive tract, near the rectum or anus. This is the kind you might notice on toilet paper, on the surface of your stool, or dripping into the bowl. It often points to hemorrhoids, anal fissures (small tears in the skin around the anus), or irritation from straining.
Black, tarry-looking stool is a different situation. When blood starts higher up in the digestive tract, such as the stomach or upper intestine, it gets broken down by digestive enzymes as it travels through. By the time it comes out, the blood has turned dark and sticky. This appearance is more concerning because it usually signals bleeding from an ulcer or another issue higher up in the gut, and it warrants prompt medical attention.
Dark red or maroon-colored blood falls somewhere in between and can come from the middle of the digestive tract, like the small intestine or the first part of the colon.
The Most Common (and Least Scary) Causes
Hemorrhoids are far and away the most frequent reason people see blood in the toilet. These are swollen blood vessels around the rectum that can bleed when you strain during a bowel movement. The blood is usually bright red, and the bleeding is painless or comes with mild itching or discomfort. Hemorrhoids are extremely common, especially during pregnancy, in people who sit for long periods, or in anyone who deals with chronic constipation.
Anal fissures are another common culprit. These are tiny tears in the lining of the anus, usually caused by passing a large or hard stool. They tend to cause sharp pain during a bowel movement along with a small amount of bright red blood. They typically heal on their own within a few weeks.
Hard or frequent stools from constipation or diarrhea can also cause minor bleeding on their own, simply from irritating the lining of the lower bowel.
When Blood Signals Something More Serious
While hemorrhoids explain most cases, blood in stool can also be a symptom of conditions that need treatment. Colon polyps, which are small growths on the inner wall of the colon, can bleed intermittently. Most polyps are benign, but some can develop into cancer over time, which is why they’re typically removed when found during a colonoscopy.
Colorectal cancer can cause rectal bleeding too, but it looks different from hemorrhoid bleeding in a few key ways. The blood tends to be more persistent, sometimes darker in color, and it usually comes with other symptoms that hemorrhoids don’t cause: unexplained weight loss, ongoing changes in bowel habits (new constipation or diarrhea that doesn’t resolve), abdominal cramping, overwhelming fatigue, or a feeling that your bowel doesn’t fully empty. If you’re experiencing a combination of these alongside blood in your stool, that’s worth getting checked out promptly.
Colorectal cancer is still uncommon in younger adults, diagnosed in roughly 2 to 6 people per 100,000 in their 20s and 30s, but rates have been climbing in people under 50. About 10% of colon cancer diagnoses now occur before age 50, most of them between ages 40 and 49. So age alone isn’t a reason to dismiss the symptom.
Inflammatory Bowel Conditions
Ulcerative colitis and Crohn’s disease are two forms of inflammatory bowel disease that commonly cause bloody stools. With ulcerative colitis, the blood is often mixed in with diarrhea and may appear alongside mucus or pus. People with this condition frequently experience belly cramps, urgent need to use the bathroom, and a frustrating inability to fully pass stool despite that urgency. In some cases, rectal bleeding is the only early sign of the disease.
Other inflammatory causes include diverticulosis (small bulging pouches in the colon wall that can bleed, sometimes heavily), proctitis (inflammation of the rectal lining), and colitis triggered by infections or reduced blood flow to the colon. These conditions all require a proper diagnosis to manage effectively.
Things That Look Like Blood but Aren’t
Before you panic, consider what you’ve eaten or taken recently. Beets and foods with red coloring can make stool look reddish. Iron supplements, black licorice, blueberries, activated charcoal, and bismuth-based medications (the active ingredient in Pepto-Bismol) can all turn stool black, mimicking the appearance of upper GI bleeding. If you suspect a food or supplement is the cause, your doctor can do a simple chemical test on a stool sample to confirm whether blood is actually present.
Signs You Need Immediate Help
A small amount of bright red blood on toilet paper after straining is usually not an emergency. But certain situations call for urgent care. Get to an emergency room if rectal bleeding is continuous or heavy, or if it comes with severe abdominal pain or cramping.
Call 911 if you’re bleeding from the rectum and also experiencing any signs of significant blood loss:
- Dizziness or lightheadedness when standing up
- Rapid, shallow breathing
- Confusion or fainting
- Cold, clammy, or pale skin
- Blurred vision
- Nausea
- Very low urine output
These symptoms suggest your body is losing enough blood to affect circulation, which requires immediate treatment.
What to Pay Attention To
If you notice blood in your stool, take note of a few things before your appointment: the color of the blood, whether it’s on the surface of the stool or mixed in, how many times it’s happened, and any other symptoms like pain, weight changes, or shifts in your bowel habits. This information helps your doctor narrow things down quickly.
A single episode of bright red blood after a hard bowel movement, with no other symptoms, is almost always something minor. Repeated bleeding, dark or tarry stools, blood mixed into the stool itself, or bleeding paired with any of the warning signs above deserves a closer look. For many people, the evaluation involves a straightforward exam and possibly a colonoscopy to visualize the inside of the colon directly.