Rumination syndrome is defined as a regurgitation of recently ingested food into the mouth with subsequent remastication and reswallowing or spitting out, and absence of structural disease. This is infrequent in adults of normal mental capacity. The true prevalence of rumination syndrome is unknown because few people have medical attention and most of physicians do not recognize this syndrome as a disease. Upper gastrointestinal manometry has been reported to show a characteristic pattern that confirms the diagnosis, namely, the occurrence of synchronous pressure spikes termed "R waves" at all levels in the stomach and small intestine. We assessed a 49-year-old male patient who complained of frequent effortless regurgitation of food. Ambulatory short-segment antroduodenal manometry with pH-metry showed simultaneous repeatetive contractions in all segments associated with regurgitation.