Medications are metabolized by the gastrointestinal (GI) system. Some types of medications can therefore directly affect an otherwise healthy gastrointestinal system.
Some pain medications and diuretics may cause constipation, as can medications used to treat high blood pressure, depression, and Parkinson's disease. Aspirin and some anti-inflammatory medications may increase the risk for peptic ulcers, especially in older adults.
Talking to a doctor about GI symptoms is important so that your doctor can evaluate whether to change medication or alter the dosing. Your doctor may also recommend dietary changes that can help prevent GI side effects.