Bleeding from your bottom is common and usually not dangerous. About 15 out of every 100 adults report experiencing it at some point, and the most frequent causes are hemorrhoids and small tears in the skin around the anus. That said, rectal bleeding can occasionally signal something more serious, so the color of the blood, how much there is, and any symptoms that come with it all matter.
What the Color of the Blood Tells You
Bright red blood, whether you see it on the toilet paper, dripping into the bowl, or streaked on the surface of your stool, almost always means the bleeding is coming from somewhere near the exit: the anus, rectum, or lower colon. This is the most common type people notice, and it’s the kind typically caused by hemorrhoids or fissures.
Dark maroon blood or blood that appears mixed into the stool suggests the bleeding is coming from higher up in the colon. Black, tarry, sticky stools point to bleeding even further up in the digestive tract, often from the stomach or small intestine, where the blood has been partially digested on its way through. If you’re seeing dark or black blood, that warrants a prompt medical evaluation even if the amount seems small.
Hemorrhoids: The Most Common Cause
Hemorrhoids are swollen veins around the anus or inside the lower rectum, and they’re by far the most frequent reason for bright red rectal bleeding. Internal hemorrhoids, the kind inside the rectum, often produce painless bleeding. You might notice bright red streaks on the toilet paper or drops of blood in the bowl after a bowel movement but feel nothing unusual otherwise. External hemorrhoids, closer to the surface, can cause a noticeable lump near the anus along with itching, discomfort, or pain.
Straining during bowel movements, sitting on the toilet for long periods, chronic constipation, and pregnancy all increase the risk. Most hemorrhoids improve on their own with more fiber, more water, and less time straining on the toilet.
Anal Fissures: Small Tears That Hurt
An anal fissure is a tiny tear in the lining of the anus, usually caused by passing a hard or large stool. The key difference from hemorrhoids is pain. Fissures typically cause a sharp, tearing pain during a bowel movement that can linger as a throbbing ache for hours afterward. You’ll often see blood on the toilet paper or on the surface of the stool, similar to hemorrhoids, but the pain is the distinguishing feature.
Most fissures heal within a few weeks with simple changes like softening your stools through diet, staying hydrated, and using warm baths to relax the muscles around the anus.
Diverticular Disease
Diverticular disease involves small pouches that form in weak spots along the wall of the colon. These pouches are extremely common as people age and usually cause no symptoms at all. Occasionally, though, a tiny blood vessel within one of these pouches can burst, causing sudden, painless bleeding that can be surprisingly heavy. The blood is typically dark red or maroon.
Diverticular bleeding often stops on its own, but because it can produce a large volume of blood quickly, it’s one of the more alarming types of rectal bleeding. If you pass a significant amount of dark red blood without pain, it’s worth getting evaluated promptly.
Inflammatory Bowel Disease
Ulcerative colitis and Crohn’s disease both involve chronic inflammation in the digestive tract, and both can cause rectal bleeding. In ulcerative colitis, bloody stools are one of the hallmark symptoms. Crohn’s disease that affects the colon produces visible rectal bleeding in roughly one out of every three cases.
What sets inflammatory bowel disease apart from hemorrhoids or fissures is that bleeding comes with other persistent symptoms: ongoing diarrhea, abdominal cramping, fatigue, unintended weight loss, or fever. If you’re bleeding and also experiencing these kinds of systemic symptoms over weeks or months, that pattern points toward something beyond a simple surface-level cause.
Medications That Increase Bleeding
Blood-thinning medications can cause or worsen rectal bleeding, particularly in older adults. Aspirin, blood-thinning prescriptions for heart conditions or blood clots, and anti-inflammatory painkillers like ibuprofen can all make it easier for bleeding to start and harder for it to stop. If you’re taking any of these and notice new rectal bleeding, it’s worth mentioning to your doctor, since the medication itself may be amplifying bleeding from a source like hemorrhoids or diverticular pouches that would otherwise be minor.
Colorectal Cancer: When to Take It Seriously
This is the worry that brings most people to a search engine, and here’s the reassuring context: colorectal cancer is a relatively uncommon cause of rectal bleeding compared to hemorrhoids and fissures. But it is a possible one, especially for people over 45, which is why screening matters.
The U.S. Preventive Services Task Force recommends that all adults begin colorectal cancer screening at age 45. For people between 50 and 75, screening is strongly recommended. The most thorough option is a colonoscopy every 10 years, which can both detect cancer and find precancerous growths before they become a problem. A simpler alternative is a stool-based test done at home each year, which checks for hidden blood in your stool. Colonoscopy is better at catching precancerous changes, but the stool test detects actual cancers at a similar rate and is easier for many people to follow through on.
Bleeding from colorectal cancer doesn’t look dramatically different from hemorrhoid bleeding on its own. What raises concern is bleeding combined with changes in bowel habits that last more than a few weeks, unexplained weight loss, a feeling that your bowel doesn’t fully empty, or new bleeding in someone over 45 who has never been evaluated.
Signs That Need Immediate Attention
Most rectal bleeding is not an emergency. But certain combinations of symptoms mean you should get help right away. Call emergency services if you’re bleeding from your bottom and also experiencing dizziness or lightheadedness when you stand up, confusion, fainting, rapid shallow breathing, cold or clammy skin, nausea, or blurred vision. These are signs your body is losing enough blood to affect circulation.
You should also get to an emergency room if the bleeding is continuous or heavy (soaking through clothing or filling the toilet bowl), or if it comes with severe abdominal pain or cramping. Even without those dramatic signs, any rectal bleeding that keeps coming back over days or weeks deserves a doctor’s evaluation, regardless of your age. Only about 14% of people who experience rectal bleeding actually bring it up with a doctor, which means the vast majority never get an explanation for what’s causing it.
What a Doctor Will Typically Do
For most people, an evaluation starts with questions about what the bleeding looks like, how often it happens, and what other symptoms you have. A physical exam of the area is standard. Depending on your age and symptoms, your doctor may recommend a colonoscopy to look at the inside of your colon directly. This is the most accurate way to identify the source of bleeding, whether it turns out to be hemorrhoids, diverticular pouches, inflammation, or something else.
For younger adults with symptoms that clearly point to hemorrhoids or a fissure, treatment often starts without any invasive testing. But for anyone over 45 who hasn’t been screened, or anyone with persistent or unexplained bleeding, a closer look is usually the right call.