Ulcer recurrence.
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000188:drug therapy; D011899:Ranitidine / Q000008:administration & dosage; D012008:Recurrence; D013997:Time Factors
D011899:Ranitidine