Role of acid and bile reflux in development of specialised intestinal metaplasia in distal oesophagus.

ABSTRACT

BACKGROUND: Barrett's oesophagus is defined as specialised intestinal metaplasia in the distal oesophagus, regardless of extension. AIM: To study distal oesophagus function, and acid and bile exposure in patients with Long Segment (>3 cm), Short Segment (1 to 2 cm) and Ultra-short Segment (<1 cm) Barrett's Oesophagus, and in patients with gastro-oesophageal reflux disease without intestinal metaplasia. PATIENTS Study population comprised 17 patients with Long, 8 with Short, 9 with Ultra-Short Segment Barrett's oesophagus, 32 with reflux disease and 12 healthy volunteers. METHODS: Patients were evaluated by manometry and by 24-hour pH and bile monitoring. RESULTS: Patients with intestinal metaplasia had greater acid exposure of the distal oesophagus than healthy volunteers. Patients with Long Segment Barrett's oesophagus had a longer history of symptoms, worse lower oesophageal sphincter pressures and longer bile and acid exposure than the other patients. Long Segment Barrett's oesophagus was predicted by low oesophageal pressure and increased bile exposure, age and male sex. CONCLUSION: Acid exposure in the distal oesophagus is probably the aetiological factor behind intestinal metaplasia, but a severely damaged antireflux barrier and bile in the refluxate are necessary for Long Segment Barrett's Oesophagus to develop.