Gastrointestinal (GI) medications have been administered to many patients without any gastrointestinal diseases. The objectives of this study were to evaluate use of GI drugs and assess related factors. Medical records of 600 outpatients were reviewed from January 1997 to December 1997 at A Hospital, Kyunggi-do, Korea. Fifty patients every month among all outpatients were randomly selected up to total 600 patients. Surgical patients, visitors for regular health examination and inpatients were excluded. GI symptoms included nausea, vomiting, diarrhea, dyspepsia, constipation, heartburn, dysphagia and abdominal pain. The prescribed gastrointestinal drugs were antacids. $H_2$-antagonist, sucralfate, cisapride, omeprazole, laxatives, digestive enzymes and antidiarrheal agents. Patients without GI symptoms were 348 out of 600 outpatients who were screened. Two hundred and eighty two of 348 patients $(81\%)$ were given GI drugs though they did not have any GI symptoms. There were no differences in regard to sex and age of patients. Most of medical departments prescribed gastrointestinal drugs for these patients. The most frequently prescribed drugs were in order of digestive enzyme, antacids and $H_2$-antagonists. In view of economic aspects, patients paid 12.28 percents of total cost per prescription for unnecessary medicines. The medical practice of prescribing GI drugs should be assessed to define appropriate subgroups to have benefits with prophylactic administration and to reduce adverse effects caused by drug interactions. Pharmacists would have a significant role to promote rational drug therapy.