A some point, we’ve all been there. Often, indigestion is caused by foods and drinks that irritate your digestive tract. Alcohol, caffeine and greasy, spicy or refined foods are all common offenders. Foods high in complex carbohydrates – like grains and legumes – are difficult to digest, and can lead to indigestion too. Even certain medicines, including aspirin, antibiotics and pain medications can send your stomach into distress.