A prospective study of oesophageal 24-h ambulatory pH monitoring in patients with functional dyspepsia.
The diagnostic utility of 24-h oesophageal ambulatory pH monitoring in patients with functional dyspepsia has not been well established. We performed a prospective study of oesophageal pH monitoring in patients with functional dyspepsia in order to assess whether a positive pH test might predict response to proton pump inhibitor therapy in a subset of functional dyspepsia patients. Forty Helicobacter pylori-negative functional dyspepsia patients (35 males and 5 females, mean age (+/-S.E.M.) of 54+/-2.4 years) with predominantly unspecified dyspepsia subtype and normal distal oesophageal biopsies. All subjects were randomised in a double-blind fashion to either omeprazole 20 mg/day or placebo daily for four weeks after 24-h pH monitoring. Twenty-four-hour pH monitoring was abnormal in 9 of the 21 patients (43%) in the omeprazole group and 5/19 (26%) of the placebo group (p=NS). Patients who reported symptomatic improvement on the Gastrointestinal Symptom Rating Scale were no more likely to have abnormal scores on pH monitoring than patients who did not have symptomatic response. Although approximately one-third of functional dyspepsia patients will have abnormal profiles on 24-h ambulatory oesophageal pH monitoring, an abnormal score does not appear to predict response to proton pump inhibitor therapy in patients with unspecified functional dyspepsia.