Red poop is usually caused by something you ate, not by bleeding. Beets, tomatoes, cherries, red candy, and foods with red artificial dyes are the most common culprits. But actual blood in the stool is also a real possibility, and knowing how to tell the difference matters.
Foods That Turn Stool Red
Beets are the most notorious offender. A pigment called betanin gives them their deep color, and your digestive system doesn’t fully break it down. The result can look alarmingly like blood in the toilet. Tomatoes, cherries, cranberries, red peppers, and red gelatin can do the same thing. Artificial food coloring is another common cause, especially from brightly frosted baked goods, red popsicles, or handfuls of colorful candy. Red drink mixes and fruit punches also qualify.
If food is the cause, the color change should clear up within a few days once the source passes through your system. You can often confirm this by thinking back to what you ate in the past 24 to 48 hours. If you had a big beet salad yesterday and your stool is red today, that’s almost certainly the explanation.
How to Tell If It’s Actually Blood
Food-related redness tends to tint the entire stool a uniform red or pinkish color. Actual blood looks different depending on where it comes from. Bright red blood that sits on top of the stool, streaks the surface, or shows up on toilet paper usually points to bleeding in the lower part of your digestive tract: the rectum, anus, or lower colon. Darker, maroon-colored blood mixed throughout the stool suggests the source is higher up.
Black, tarry stool is a separate concern entirely. That appearance typically means blood has been digested on its way through the upper digestive tract (the stomach or small intestine), which turns it dark. Iron supplements and bismuth-based medications like Pepto-Bismol can also make stool black without any bleeding involved.
Common Causes of Blood in Stool
Hemorrhoids are the most common reason for bright red blood in or on stool. These are swollen veins in the rectum or anus, and they often develop from straining during constipation. They’re rarely dangerous, though they can be uncomfortable and persistent. Anal fissures, which are small tears in the skin around the anus, are another frequent cause, especially in people dealing with hard stools.
Beyond those two, several other conditions can cause red or bloody stool:
- Diverticulitis: Small pouches in the colon wall become infected and inflamed, making blood vessels inside them more fragile and likely to rupture.
- Inflammatory bowel disease (IBD): Conditions like Crohn’s disease and ulcerative colitis cause ongoing inflammation in the intestinal lining, which can produce bloody stool over weeks or months.
- Infections: Bacterial infections like E. coli and C. diff can cause bloody diarrhea. Gastroenteritis from food poisoning or travel can do the same.
- Colon polyps and colorectal cancer: Abnormal tissue growths in the colon can bleed when irritated or damaged. This is less common than hemorrhoids but important to rule out, particularly if you’re over 45 or have a family history.
The risk that rectal bleeding signals colorectal cancer increases with age. A large population study found that among people who visited a primary care doctor with rectal bleeding, the overall cancer risk was low (roughly 1 to 3 percent depending on sex and cancer location) but climbed in older age groups. Persistent or recurring bleeding is worth investigating regardless of your age.
Medications That Cause Red Stool
Certain medications can turn stool red without any bleeding. The most well-documented example is an antibiotic called cefdinir, which reacts with iron in supplements or fortified formulas to produce a red or maroon stool. This is harmless but alarming if you’re not expecting it. The color change happens because of a chemical interaction between the drug and iron, not because of blood. If you or your child recently started an antibiotic and are also taking iron, this is a likely explanation.
Red Stool in Babies and Children
Parents understandably panic at the sight of red in a diaper, but many causes in infants and young children are benign. Newborns sometimes swallow small amounts of blood during delivery or while breastfeeding from cracked nipples. Severe diaper rash can cause visible bleeding around the anus. Female newborns can even pass a small amount of vaginal blood shortly after birth due to a temporary hormonal effect from the mother, sometimes called “false menses.” Blood in urine, especially in young girls, can also be mistaken for blood in the stool.
In toddlers and older children, anal fissures from constipation during toilet training are the most common cause of blood on the stool. Food allergies (particularly cow’s milk protein allergy in infants) and infections from contaminated food or contact with other children can also lead to bloody stool. A sudden onset of severe abdominal pain with bloody, jelly-like stool in a young child can signal intussusception, a condition where part of the intestine folds into itself, and that requires emergency care.
When Red Stool Is an Emergency
Most cases of red stool are either dietary or caused by minor issues like hemorrhoids. But certain combinations of symptoms signal significant blood loss that needs immediate attention. Call emergency services if you notice rectal bleeding along with any of these signs:
- Rapid, shallow breathing
- Dizziness or lightheadedness when you stand up
- Fainting or confusion
- Cold, clammy, or pale skin
- Blurred vision
- Very low urine output
You should also get to an emergency room if the bleeding is continuous or heavy, or if it comes with severe abdominal pain or cramping. These symptoms can point to significant internal bleeding that needs to be located and stopped quickly.
For isolated, small amounts of bright red blood on toilet paper or the stool surface, especially if you’ve been constipated, the situation is far less urgent. But if it keeps happening for more than a week or two, or if it’s a new symptom you’ve never experienced, getting it checked gives you a clear answer and catches anything that needs treatment early.