MEPRASIL® is a brand of Omeprazole, a proton pump inhibitor used in the management of peptic ulcer diseases and other acid related disorders. Frequently reported gastrointestinal disturbances includes diarrhea (3%) and constipation (1.1%). Other gastrointestinal effects, such as abdominal pain and nausea/vomiting, may not be statistically significant when compared with placebo.