What is stool color?
Stool is naturally brown due to the digestion of bile salts produced by the liver and blood pigments such as bilirubin. Dietary supplements including iron, medications, and some foods, such as blueberries, beets, or black licorice, can darken the stool or even turn it black. Dark stool, when not associated with diet, supplements or medications, can be a worrisome symptom, as it can be due to bleeding in the digestive tract.
The color of bloody stool depends on the site of the bleeding and how quickly food moves through the digestive system. Blood from the esophagus, stomach, and small intestine may have time to be digested, resulting in dark, tarry stool. Red blood in the stool frequently comes from the lower portion of the digestive tract, specifically the colon or anus. However, bleeding from a higher portion of the digestive tract can speed digestive transit, also leading to red stool. Red striping of the stool is often related to bleeding of the rectum or anus and may be seen in stool of people who have hemorrhoids (inflamed veins in lower rectum or anus).
Pale stool can occur if bile salt production is reduced or its transport is blocked due to serious liver infections or a bile duct obstruction that is caused by stones, scarring, abnormal development, or external compression. Liver disease and bile duct obstruction can also cause jaundice, a yellowing of the skin and whites of the eyes that may be accompanied by itching.
Changes in stool color can be related to diet, supplements or medications; however, stool that is persistently dark or light can be an indication of a serious medical problem. Seek immediate medical care (call 911) for bloody stool, which may be red or black or tarry in consistency, and may be accompanied by severe pain, profuse sweating, alterations in level of consciousness, rapid heartbeat (tachycardia), vomiting blood, or chest pain.
If your stool color changes are persistent or cause you concern, seek prompt medical care.
What other symptoms might occur with stool color?
Changes in stool color are generally related to the digestive tract, whether caused by food, supplements or medications, or due to something more serious such as digestive tract bleeding, liver problems, or obstruction of the bile ducts.
Digestive symptoms that may occur along with stool color changesStool color changes may accompany other symptoms affecting the digest... Read more about stool colorsymptoms
What causes stool color?
Stool color is due to digestion of bile salts produced in the liver and can be influenced by diet, medications or supplements. Bleeding in the digestive tract can cause red, dark or black stool. Liver problems and conditions causing obstruction of the bile ducts can cause pale stools.