Alpha Femme Keto Genix Ulcers can be a cause of bleeding, and the condition is most associated with the stomach or duodenum, the first segment of small intestine after the stomach. This condition gives you the tarry, smelly stools. It was once thought that all kinds of things led to ulcers, but most of the time, they are caused by a bacteria, called h. pylori. Your doctor will prescribe an antibiotic and it should clear up.