2. Medication and Bowel Changes
If you take a prescription medication, it might cause diarrhea. Certain meds, such as metformin, antibiotics, antacids, and NSAIDs, can all cause loose stools.
Some OTC meds can lead to color changes too. Pepto Bismol is notorious for causing black stool. However, the discoloration is always temporary and harmless.
1. Bloody Stool
Any time you notice blood in your stool, there is cause for alarm. The bloody stool can indicate cancer, peptic ulcers, anal fissures, hemorrhoids, and a variety of other conditions. If there is blood in your stool, then it might appear bright red or the stool might simply be black and tar-like.