Diurnal variation in intragastric pH in children with and without peptic ulcers.

Diurnal variation in intragastric pH in children with peptic ulcers has not been previously reported. Therefore, we monitored intragastric pH during a 24-h period in 82 subjects (10 children with gastric ulcers, 9 children with duodenal ulcers, 58 non-ulcer (comparison group) children, and 5 healthy adults) using a monopolar glass pH electrode. The percent of readings below pH 2, 3, 4, and 5 for each subject was calculated and compared between the comparison group and the two ulcer groups using means and slopes (i.e. changes in percent with age for each group) of percent readings for each pH analysis. In the comparison group children, gastric acidity increased with age and reached adult levels by 14 y. Mean readings for all pH analyses in gastric ulcer children were lower than those in age-adjusted comparison children (p < 0.05). The slopes of the relationships between age and the percent time below any pH for the gastric ulcer group were different from those in the comparison group (p < 0.05) and were negative for all pH analyses. The mean time below pH 2 in children with duodenal ulcers was greater than that in age-adjusted comparison children (p = 0.002). The slope of the relationship between age and the percent time below pH 2 in the duodenal ulcer group was different from that in the comparison group (p < 0.05). Gastric acidity in children with primary gastric ulcers was reduced during childhood, but in children with primary duodenal ulcer, gastric acidity was at or above adult levels.