Foods That Cause (or Look Like) Blood in Your Stool, and When to Worry

If you notice blood in your toilet bowl or on your toilet paper after a bowel movement, you're likely to be concerned. There are many reasons your stool could contain blood, and while most causes are fairly harmless, blood can sometimes indicate a more serious condition.

Here, learn the causes of bloody stool, foods that cause stool to appear red and treatment options.

While certain foods and drinks can irritate your digestive tract lining and cause bloody stools, per Johns Hopkins, other red foods can create the illusion of bloody stool without any actual blood. Read below to learn more about possible causes.

Before you start panicking, certain red foods like tomato juice can cause red stool, or bloody-appearing stool.

"There are certain red foods that may cause the appearance of blood," says Daniela Jodorkovsky, MD, director of the Center for Gastrointestinal Motility and Physiology at Columbia University Medical Center, including:

• Beets
• Red Jell-O
• Tomato juice
• Watermelon
• Cranberries
• Anything with a lot of red food coloring

Other foods, according to the University of Iowa Hospitals & Clinics, can cause stool to appear darker than usual, including:

• Black licorice
• Blueberries
• Large amounts of dark, leafy veggies
• Iron supplements

In this case, it's worth recalling what you've eaten recently to see if red or dark food is the culprit.

Some foods, like coffee, can cause bloody stools by irritating your digestive tract lining, per Johns Hopkins. This can lead lead to swollen, irritated intestines — also known as gastritis.

Foods that can cause, or further, this type of irritation include:

• Spicy foods, like hot peppers or hot sauce
• Fatty or fried foods
• Caffeine
• Alcohol

You may also experience bloody stools after eating dairy products, such as milk, if you have an allergy, per the American College of Allergy, Asthma & Immunology (ACAAI).

That said, there are other causes for bloody stools beside food.

If you haven't eaten anything out of the ordinary recently, you might consider another cause for blood in your stool: constipation. If you've had trouble passing bowel movements, "there's a possibility that the hard stool may be irritating your anal tissue on its way out," says Donald Ford, MD, a Cleveland Clinic family medicine physician.

Hemorrhoids (swollen veins in your anus or lower rectum) are benign and treatable conditions. Internal hemorrhoids, while typically painless, can cause blood spotting and bloody stool on its way out, per Harvard Health Publishing.

Anal fissures (small tears in the lining of your anus) can form when you have constipation or diarrhea, resulting in bloody stool, per the University of Iowa Hospitals & Clinics. Anal fissures can cause an itchy butt, burning and a visible crack on the anus.

If you find blood in your stool often, there are certain foods you can eat to reduce it, according to University of Utah Healthcare, including:

• ‌Whole grains‌ like wheat bran, corn bran and brown rice
• ‌Vegetables‌ like carrots, broccoli, cabbage and peas
• ‌Fruits‌ like apples, bananas, raspberries, peaches, prunes and pears
• ‌Nuts and legumes‌ like peanuts, lentils and kidney beans

In addition to eating these foods, aim to drink 8 to 10 cups of water per day and to get regular exercise.

"Seeing blood in the stool is always alarming," Dr. Ford says. "While I would never turn a patient away if they came in with this concern, most occurrences are nothing to worry about."

Once you've ruled out constipation and red foods, bloody stool accompanied by abdominal pain, cramping, fever or diarrhea could indicate a more serious digestive issue — such as the inflammatory bowel diseases called Crohn's disease or ulcerative colitis, according to the Mayo Clinic.

In this case, a gastroenterologist may decide to run a test on your stool that identifies microscopic amounts of blood, called a fecal occult blood test, according to the Mayo Clinic. This can help narrow your diagnosis and provide accurate treatment.

That said, both Drs. Ford and Jodorkovsky point out certain elements can cause false positives or false negatives in the fecal occult blood test. These include red meat, turnips, broccoli, horseradish and vitamin C supplements.

It's important to avoid these foods and supplements for several days before the test.

Because there are so many potential causes for blood in the stool — most of which are benign — it's better not to jump to the conclusion that you have cancer. Having said that, consistent bleeding or dark and tarry stool accompanied by changes in your bowel habits, or very narrow stool, could be a sign of colon cancer, according to the American Cancer Society.