What Causes Dark Stool? 11 Possible Causes You Should Know

As its name implies, black or dark stool essentially refers to conditions wherein excrement takes on an unusually dark color. While the darkening of stool can be expected as a normal response or occurrence to specific medications, supplements, or food, it can also indicate an underlying condition or medical problem. If food-related, black licorice, blueberries, or beats are common causes because stool that passes after their consumption tends to be black, reddish, bluish, and dark brown. 

Medications and iron supplements that contain bismuth subsalicylate and other anti-diarrhea drugs may also contribute to the darkness of the stool color. In most cases, it isn’t something to get worried about. However, if a person has a history of gastrointestinal bleeding, the stool has an incredibly foul smell. If the issue lasts too long, it’s a good idea to reach out to a healthcare provider to rule out health problems, ease out, and put any worries to rest.

This article will cover some of the most common causes of tarry or dark stools and explain potentially serious medical problems associated with the condition. If you want to learn more, continue reading. 

Supplements and Food

Underlying health problems don’t always cause dark stools. More often than not, they’re generally brought about because of supplements, medication, minerals, or food consumed. For example, iron supplements, whether taken as a part of multivitamins or alone to overcome iron-deficiency anemia, can potentially cause green or black stools. Additionally, as mentioned previously, specific types of food that are green, dark blue, or black may result in darkened bowel movements. 

For those unable to trace their dark stools to supplements or food taken, it’s highly advised to consult with a medical professional to explore other potential causes for the condition and ensure that it isn’t a symptom of a serious health-related problem. If no obvious causes can be found, it’s often best to check if any blood can be found in the excrement. While there are various medical causes for black, tarry-textured stools, a good indicator of the condition is if there’s a malodorous or foul smell. It’s because foul-smelling and dark stools are common symptoms of GI bleeding, specifically from the small intestine, esophagus, or stomach.