“…More recent follow-up studies on the clinical course of ulcer disease have been reported by Natvig et al (21) and Qvigstad and Romcke (23), Krarup (14), Flood (6) and Malmros and Hiertonn (18). These studies have the following features in common: average observation periods of 5-10 years; a high follow-up percentage and a reliable diagnostic technique based on barium-meal examinations.…”