How Can I Tell If Blood is in My Stool?

Finding blood in the toilet after excreting waste can indeed be shocking. However, the appearance of blood in the toilet after using the bathroom does not necessarily mean there is blood in your stool. For example, severe constipation can scrape the inner walls of your anus. Also, according to the National Institute of Health, certain types of ulcers and hemorrhoids can also lead to blood either in or around your stool. However, bloody stool can also be an indicator of more severe types of disease, like colon cancer, so it should not be taken lightly.

Determine whether there is blood in or on your feces or whether there is only blood on the toilet paper when you wipe. If there is only blood on the toilet paper when you wipe, it may mean you have an anal fissure, which is a crack or tear in the skin of your anal canal. Although anal fissures normally occur in infants, they can happen at any age, especially after severe constipation. Anal fissures are also common in women after childbirth and persons with Crohn's disease.

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Examine the amount of blood that accompanies your feces. If at all possible, try to determine whether the blood is outside of your feces, just coating it or if it is mixed through and through, as might be the case with bloody diarrhea.

Note the color of the blood in or on your feces. Blood in your stool can come from anywhere along your digestive tract. Black stool usually indicates that the blood is coming from the upper part of the gastrointestinal tract, including the esophagus, stomach and the first part of the small intestine. However, bright red blood usually suggests that the blood is coming from the lower part of the GI tract, which includes your large bowel, rectum or anus.

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Recall the types of food or medicines you may have taken within eight to 12 hours preceding the bowel movement in question. Blueberries, black licorice, beets and tomatoes can cause black or red stools. Iron pills, lead or certain medicines containing bismuth, like Pepto-Bismol, can cause stool to appear black.

Contact your physician immediately. The spectrum of problems that can cause bloody stool is very wide, with anal fissures on the less serious end to severe gastrointestinal problems and colon cancer on the more severe side. Your doctor may use endoscopy or special X-ray studies to determine the causes of the bloody stool.


If any amount of blood appears with or in your stool, or if it occurs more than once, you should contact a physician immediately.