A total of 98 patients, who had undergone gastric surgery (23), or who had peptic ulcers (56), or who had normal endoscopic findings (19) underwent gastric biopsy, together with measurement of pH and total bile acid concentration, in their fasting gastric juice. The biopsy specimens were stained by the Warthin-Starry method for Campylobacter like organisms and were also graded "blind," as described in the preceding paper, for the five features that we believe may constitute the histological picture of reflux gastritis. The individual grades were added together to give a composite "reflux score" (0-15) for each patient. We found a notable association between the absence of Campylobacter like organisms and previous surgery for peptic ulceration, high reflux scores (greater than 10), hypochlorhydria (pH greater than or equal to 4), and increased bile acid concentrations (greater than or equal to 1 mmol/l) in the stomach. These findings further support our contention that reflux gastritis represents a distinct histopathological entity causally related to the effects of enterogastric reflux on the gastric mucosa and suggest that there may be two major categories of chronic gastritis: chronic superficial, or atrophic gastritis related to Campylobacter like organisms and reflux gastritis. Our data also imply that patients with peptic ulceration may, after gastric surgery, revert from being positive for these organisms to being negative and may undergo a possible transition from Campylobacter related chronic gastritis to reflux gastritis.