The document summarizes short-term side effects of PPIs (proton pump inhibitors), which are generally well tolerated. The most common side effects are headache, diarrhea, abdominal pain and nausea. Diarrhea appears to be related to acid suppression and the overall incidence is less than 5%, though it may be dosage and age related. PPIs are considered safe for short-term use and have similar safety profiles to H2 blockers. PPIs should be used cautiously in patients with liver disease.