AIM: To investigate the influences of bile reflux on profiles of gastric mucosal lesions in patients with dyspepsia or chronic gastritis. METHODS: A total of 49 patients diagnosed with dyspepsia and chronic gastritis underwent 24-h ambulatory and simultaneous monitoring of intragastric bilirubin absorbance and pH values, and then they were divided into bile reflux positive group and bile reflux negative group. Severity of pathological changes in gastric mucosa including active inflammation, chronic inflammation, intestinal metaplasia, atrophy and dysplasia as well as Helicobacter pylori (H pylori) infection at the corpus, incisura and antrum were determined respectively according to update Sydney system criteria. The profiles of gastric mucosal lesions in the two groups were compared, and correlations between time-percentage of gastric bilirubin absorbance >0.14 and severity of gastric mucosal lesions as well as time-percentage of gastric pH >4 were analyzed respectively. RESULTS: Thirty-eight patients (21 men and 17 women, mean age 44.2 years, range 25-61 years) were found existing with bile reflux (gastric bilirubin absorbance >0.14) and 11 patients (7 men and 4 women, mean age 46.2 years, range 29-54 years) were bile reflux negative. In dyspepsia patients with bile reflux, the mucosal lesions such as active inflammation, chronic inflammation, intestinal metaplasia, atrophy or H pylori infection in the whole stomach, especially in the corpus and incisura, were significantly more severe than those in dyspepsia patients without bile reflux. Moreover, the bile reflux time was well correlated with the severity of pathological changes of gastric mucosa as well as H pylori colonization in the near-end stomach, especially in the corpus region. No relevance was found between the time of bile reflux and pH >4 in gastric cavity. CONCLUSION: Bile reflux contributes a lot to mucosal lesions in the whole stomach, may facilitate H pylori colonization in the corpus region, and has no influence on acid-exposing status of gastric mucosa in patients with dyspepsia or chronic gastritis. AIM: To investigate the influences of bile reflux on profiles of gastric mucosal lesions in patients with dyspepsia or chronic gastritis. METHODS: A total of 49 patients diagnosed with dyspepsia and chronic gastritis underwent 24-h ambulatory and simultaneous monitoring of intragastric bilirubin absorbance and pH values, and then they were divided into bile reflux positive group and bile reflux negative group. Severity of pathological changes in gastric mucosa including active inflammation, chronic inflammation, intestinal metaplasia, atrophy and dysplasia as well as Helicobacter pylori (H pylori) infection at the The profiles of gastric mucosal lesions in the two groups were compared, and correlations between time-percentage of gastric bilirubin absorbance> 0.14 and severity of gastric mucosal lesions as well as time -percentage of gastric pH> 4 were analyzed respectively. RESULTS: Thir ty-eight patients (21 men and 17 women, mean age 44.2 years, range 25-61 years) were found with bile reflux (gastric bilirubin absorbance> 0.14) and 11 patients (7 men and 4 women, mean age 46.2 years, In dyspepsia patients with bile reflux, the mucosal lesions such as active inflammation, chronic inflammation, intestinal metaplasia, atrophy or H pylori infection in the whole stomach, especially in the corpus and incisura, were significantly more severe than those in dyspepsia patients without bile reflux. Moreover, the bile reflux time was well correlated with the severity of pathological changes of gastric mucosa as well as H pylori colonization in the near-end stomach, especially in the corpus region. No relevance was found between the time of bile reflux and pH> 4 in gastric cavity. CONCLUSION: Bile fluid contributes a lot to mucosal lesions in the whole stomach, may facilitate H pylori colonization in the corpus region, and has no influence on acid-exposing status of gastric mucosa in patients with dyspepsia or chronic gastritis.