It is generally advised not to drink alcohol while taking Pepto-Bismol. The active ingredient in Pepto-Bismol, bismuth subsalicylate, and alcohol are both processed, at least partly, by the liver. Drinking alcohol while taking Pepto- Bismol can strain the liver, potentially causing damage and impairing how the body metabolizes both substances. Additionally, combining alcohol and Pepto- Bismol may increase the risk of gastrointestinal bleeding, especially if there are ulcers or sensitive areas in the stomach lining. Also, alcohol itself irritates the stomach lining, which Pepto-Bismol is meant to soothe, so drinking alcohol may counteract the benefits of Pepto-Bismol for stomach upset. If Pepto-Bismol is taken after drinking, it's important to watch for signs of gastrointestinal bleeding such as bright red or dark blood in the stool, although Pepto-Bismol can also cause black stools, which is not necessarily a problem. While some older studies have not found concrete evidence of harm from taking Pepto-Bismol after drinking, medical advice generally favors avoiding combining them for safety reasons. For hangover stomach discomfort, hydration and bland foods are safer remedies than relying on Pepto-Bismol. In summary, it is best to avoid drinking alcohol while using Pepto-Bismol due to potential liver strain, stomach irritation, and bleeding risks.