This study compared changes in intragastric pressure (IGP) in response to a gastric distension stimulus caused by air insufflation in 25 patients with non-erosive gastro-oesophageal reflux disease (NERD) and 34 healthy volunteers (controls). In four NERD patients, IGP responses were also measured before and after oral treatment with 10 mg rabeprazole daily for 2 weeks. The rate of increase in IGP at the start of insufflation was significantly higher in NERD patients than in controls. The time to appearance of symptoms (i.e. time to threshold) was significantly shorter in NERD patients than in controls. Direct measurement of IGP showed that visceral hypersensitivity and impaired fundal relaxation are both characteristic of NERD. Administration of rabeprazole led to a marked prolonging of time to threshold, indicating that treatment could alleviate this hypersensitivity.