[Comparison of 24-hour gastric pH in normal controls and patients with duodenal ulcer or atrophic gastritis].

Twenty-four intragastric acidity was measured by continuous recording using intragastric glass electrodes in 16 normal controls, 18 inactive duodenal ulcer patients and 7 patients with atrophic gastritis. Median pH for the 24 h period, for the 8 AM-8 PM period, and for the 8 PM-8 AM period were significantly lower in duodenal ulcer patients than in controls (1.19 vs 1.78; 1.17 vs 2.05; 1.27 vs 1.64). Median pH for these 3 periods were significantly higher in patients with atrophic gastritis than in controls (3.90; 3.72; 3.81). The median pH for the 24 h period was higher than the lower quartile value of the control group in 33 per cent of duodenal ulcer patients. During the night (24 h-3 h), duodenal ulcer patients had significantly lower median pH (1.03) than controls (1.51). Antisecretory treatment should be directed to decrease this period of unbuffered acidity.