Gastric acid output, however, is not changed by treatment of the infection.

Johnson et al suggested that changes in urine and gastric acid output were linearly related.

The sham feed produced a transient rise in gastric acid output that was most marked in the 30 minutes after feeding (Fig 1).

We have not found a diminution in gastric acid output in old subjects with histologically normal stomachs under basal or stimulated conditions.

This study shows that chronic H pylori infection is accompanied by appreciably increased gastric acid output in both healthy volunteers and duodenal ulcer patients.

Residual gastric contents were discarded, and basal gastric acid output was determined by collection of gastric contents at 15 minute intervals for 45 minutes.

Measurement of the urine alkaline tide as an index of gastric acid output, has been proposed as a non-invasive alternative to conventional gastric secretion studies.

The gastric contents were collected at 15 minute intervals for 45 minutes to determine stimulated gastric acid output, after which the nasogastric tube was removed and subjects once more emptied their bladders.

In summary, we have developed a non-invasive test which predicts accurately gastric acid output in populations with high prevalences of achlorhydria and is suitable for field use for population studies of young children in developing countries.

It is concluded that the unchanged gastric acid output after eradication of H pylori is a more important factor in the development of gastric metaplasia than the H pylori related inflammatory process.

The most consistent fall in UAO was seen after breakfast, and suggested that a light meal after a relatively long fast provided the ideal stimulus for observing changes in UAO that reflect gastric acid output.

Measuring changes in urine acid output at breakfast time provides a reliable indirect measure of gastric acid secretion that can be used in field conditions, enabling the relation between gastric acid output and the development of diarrhoeal diseases to be investigated.