You wouldn’t hesitate to tell your doctor if you had a persistent cough or recurring headaches, but there are some symptoms that can feel uncomfortable to bring up. Take blood in the stool. Maybe you’ve noticed blood in the toilet bowl or when you’ve wiped after a bowel movement, and you’re hoping that it will stop before you have to mention it to your doctor.
Don’t wait—tell your doctor right away.
“It’s never normal to have blood in your stool, and it can be a sign of some significant health issues that are nonetheless very treatable if caught early,” says UNC Health gastroenterologist Michael Dougherty, MD. “Some people find anything to do with stool or the rectum to be embarrassing, but it’s really important to talk to a doctor about this. It’s part of our job and not embarrassing to us, so tell us.”
Causes of Blood in Stool
Rectal bleeding or bloody stool is a symptom of many conditions.
“The most common cause of bloody stool is hemorrhoids,” swollen veins in the anus or lower rectum, Dr. Dougherty says. “They could be internal hemorrhoids so you don’t necessarily see or feel them.”
Bloody stool could also be caused by anal fissures (tears in the anal tissue), inflammation in the colon or rectum, inflammatory bowel disease (which includes ulcerative colitis and Crohn’s disease) and diverticulosis (a condition in which blood vessels associated with small pockets that have formed in the colon rupture). It may also indicate a viral, bacterial or parasitic infection, particularly if you’re also having diarrhea.
While these common causes of bloody stool are benign, it’s also a symptom of colorectal cancer, which has been increasing in people younger than 55 in recent years. It’s the third most common cancer in both men and women in the United States, excluding skin cancers.
Some medications may slightly increase your risk for bloody stool; nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen can cause inflammation, which may lead to bloody stool, but Dr. Dougherty says this is not as common as other causes. Some blood thinners may result in increased bleeding, but they aren’t the direct cause.
“Even if you’re on a blood thinner, it’s still not OK to see blood in the stool,” Dr. Dougherty says. “The medications can make a source of bleeding worse, but determining the cause is still important.”
Babies and children also can experience bloody stool or rectal bleeding and the symptom should be reported to their pediatrician promptly. In addition to fissures, hemorrhoids, infection and inflammatory bowel disease, bloody stool in children might also indicate a food intolerance or an intestinal obstruction.
What to Do If You See Blood in Your Stool
If you see a high volume of blood in your stool, or if you’re actively bleeding from your rectum, go to urgent care or the emergency department. Diverticulosis can cause severe bleeding that requires emergency care.
But even if the bleeding isn’t severe, Dr. Dougherty recommends telling your primary care provider any time you see blood.
Take note of how the blood appears so you can tell your doctor: Is it just on the surface of the stool, or mixed within? What color is the blood? But resist the urge to search the internet for answers.
“It’s going to be hard for you to say for sure based just on appearance that it’s harmless, so it needs evaluation regardless of appearance,” Dr. Dougherty says. “Your doctor may do a rectal exam, stool tests or a blood test to check for infections and anemia, but the best and most reliable test is a colonoscopy.”
A colonoscopy is especially important if you’re having additional symptoms, such as changes in bowel habits or stool shape, unintended weight loss or abdominal pain.
“The guideline for a colonoscopy as a screening tool is to start at age 45, but that’s if you’re asymptomatic and feeling great,” Dr. Dougherty says. “If you’re having bloody stool, you’re no longer within those screening guidelines and will need one earlier. If you’re having this symptom, it’s a diagnostic colonoscopy, not a screening.”
While it’s normal to be nervous about a colonoscopy, having the test can help your provider understand what’s going on and start you on any relevant treatments as soon as possible. And because so many benign conditions cause bloody stool, that may mean you won’t need any treatment—hemorrhoids, for example, may only require treatment if they become more bothersome to you.
But you will only know if you mention the symptom to your doctor.
“People need to be more open about this subject—blood in stool and the possibility of colorectal cancer—in general,” Dr. Dougherty says. “It’s important to know your family history, to know if your parents have a history of polyps. Be up-to-date on your screenings, and if you have this symptom, don’t be shy.”
If you experience bloody stool, talk to your doctor. If you need a doctor, find one near you.