[Circadian rhythms of acid production and alkalization in the stomach of healthy subjects and duodenal ulcer patients].

We studied 24-h rhythms of acid production and alkalization in 30 patients with duodenal ulcer (DU) and 30 healthy subjects using upper endoscopic examination and computer intragastric pH-metry. Gastric acid production was higher in DU patients and was more intensive in the daytime than at night. Healthy subjects had low and monotonous acid production. In DU decompensation of alkalization in the antral stomach and suppression of duodenogastric reflux is total. In healthy subjects antrum alkalization is more evident and intensive at night due to, among other causes, duodenogastric reflux.