4. Bleeding Ulcer
One health issue that is fairly common when it comes to stools that are dark in color is an ulcer. Ulcers are sores that develop in your small intestine or stomach. These sores can cause all sorts of health issues. At times, if the sores open up, they will start to bleed. When an ulcer begins to bleed, your stool may become darker in color. This is because of the blood that is getting into your stool.
Some of the other symptoms of an ulcer include a burning sensation in your stomach, burping, heartburn, swelling in your abdomen, and at times nausea. You may even vomit and the vomit will often look like coffee grounds. There are medications that you can take for an ulcer that may help to lower the amount of acid in the stomach. Some other medications work by coating the lining of the stomach as a way to protect it from the damage that is caused by a build-up of acid.