Red stool is usually caused by something you ate, not something dangerous. Beets, red food dyes, tomato-based sauces, and certain medications can all turn your poop shades of red, pink, or maroon without any bleeding involved. That said, red stool can also signal actual blood in your digestive tract, so knowing how to tell the difference matters.
Foods and Drinks That Turn Stool Red
Beets are the most well-known culprit. The deep red pigment in beets can survive digestion, especially if your stomach acid doesn’t fully break it down, and end up coloring your stool a reddish amber. This can look alarming if you’ve forgotten about the beet salad you had the night before. The color typically shows up within 12 to 24 hours and clears within a day or two.
Other common offenders include blackberries, cranberries, tomato soup or juice, red gelatin, and anything with heavy red food coloring like punch, popsicles, or candy. If you recently ate any of these, that’s the most likely explanation. One simple check: think back over the past 24 to 48 hours. If you can identify a red food, wait a day or two and see if the color returns to normal.
Medications That Change Stool Color
Several medications produce red or orange-red stool that has nothing to do with bleeding. The antibiotic cefdinir, commonly prescribed for ear infections, is a frequent cause in children. When cefdinir combines with iron (often from iron-fortified formula), it forms a compound that turns stool red or maroon. These stools test negative for blood, and the color goes back to normal once the medication is stopped.
Other medications that can shift stool toward red or pink include rifampin (used for tuberculosis), certain laxatives containing senna, and some B12 supplements. If you recently started a new medication and noticed a color change, check the side effects or ask your pharmacist before assuming the worst.
What Actual Blood in Stool Looks Like
When blood is the cause, the color tells you roughly where the bleeding is happening. Bright red blood, often visible on toilet paper, coating the stool, or dripping into the bowl, typically comes from the lower part of the digestive tract: the colon, rectum, or anus. Darker maroon or burgundy-colored stool can indicate bleeding higher up in the colon. Black, tarry stool with a distinctive foul smell usually means blood from the upper digestive tract (stomach or esophagus) that has been partially digested on its way through.
A key difference from food-related redness: blood in stool often appears streaked on the surface, mixed unevenly, or shows up as distinct clots rather than a uniform color change throughout.
Common Causes of Rectal Bleeding
Hemorrhoids are by far the most common reason for bright red blood in stool. These swollen veins inside the rectum or around the anus sit close to the surface and can bleed when irritated by straining, hard stools, or prolonged sitting. The bleeding is typically small in volume, painless, and shows up as bright red streaks on the stool or toilet paper.
Anal fissures, which are small tears in the lining of the anus, are another frequent cause. These tend to produce a sharp pain during bowel movements along with a small amount of bright red blood. They’re common after passing particularly hard or large stools and usually heal on their own within a few weeks.
Diverticular disease, where small pouches form along the colon wall, can cause sudden, painless bleeding that’s sometimes heavy. Inflammatory bowel disease, which includes ulcerative colitis and Crohn’s disease, causes chronic inflammation in the digestive tract. Ulcerative colitis in particular often presents with bloody diarrhea, abdominal cramping, fatigue, and weight loss. Symptoms tend to develop gradually and come in cycles of flare-ups and remission. Colorectal cancer is a less common but serious cause of blood in stool, which is why routine screening is recommended starting at age 45.
Red Stool in Babies and Young Children
In infants, blood-streaked or mucousy stool is most commonly caused by a condition called allergic proctocolitis. It typically appears within the first month of life in otherwise healthy, well-nourished babies. The cause is a reaction to proteins in cow’s milk or soy, whether the baby is breastfed (with the mother consuming dairy or soy) or formula-fed. The good news: once the triggering protein is removed from the diet, bleeding usually stops within 72 to 96 hours, and most babies outgrow the condition by 12 months.
For toddlers and older children, red stool from food dyes, fruit punch, or beets is common. The cefdinir-plus-iron reaction mentioned earlier is another frequent cause of alarming but harmless red stool in kids on antibiotics.
How Doctors Test for Blood in Stool
If you’re unsure whether the red color is blood or food, a fecal immunochemical test (FIT) can detect hidden blood in stool. It’s a simple at-home kit: you brush a small sample from the surface of your stool onto a test card and send it to a lab. A positive result means blood was detected and a colonoscopy is typically the next step to find the source.
For routine colorectal cancer screening, both the American Cancer Society and the U.S. Preventive Services Task Force recommend starting at age 45 and continuing through age 75. Options include a FIT test every year, a stool DNA test every one to three years, or a colonoscopy every 10 years.
Signs That Need Immediate Attention
Most causes of red stool are either harmless (food, medications) or manageable (hemorrhoids, fissures). But certain combinations of symptoms point to something more urgent. Heavy bleeding that doesn’t stop, stool that’s consistently dark maroon or black and tarry, or red stool paired with vomiting blood all suggest significant bleeding in the digestive tract.
Physical signs of serious blood loss include feeling lightheaded or dizzy, a racing heartbeat, unusual fatigue or weakness, and pale skin. If red stool comes with any of these symptoms, or if you’re passing large amounts of blood, that warrants emergency care rather than a wait-and-see approach.