AIM:To investigate the incidence of nocturnal dyspeptic symptoms in patients with functional dyspepsia(FD) and whether prokinetic drugs can alleviate them. METHODS:Eighty-five consecutive Chinese patients with FD were included in this study.One week after single-blinded placebo run-in treatment,baseline nocturnal intragastric pH,bile reflux and nocturnal dyspeptic symptoms of eligible patients,including epigastric pain or discomfort,abdominal distention and belching, were investigated with questionnaires.Patients exhibiting nocturnal dyspeptic symptoms were randomly and double-blindly assigned to domperidone group or placebo group.Nocturnal intragastric pH and percentage of duodenogastric bile reflux time were determined after treatment. RESULTS:Of the 85 FD patients,2 females withoutnocturnal symptoms,who responded to placebo run-in treatment,were excluded from the study,30(36.1%) exhibited nocturnal dyspeptic symptoms with increased duodenogastric bile reflux time(intragastric bilirubin absorbance>0.14)and mean gastric pH(confirming the existence of bile reflux)(P=0.021,0.023) at night were included in the study.Of these 30 patients,21(70%)had overt nocturnal duodenogastric bile reflux,which was significantly higher than that of those without nocturnal symptoms(P=0.026).The 30 patients were allocated to domperidone group or placebo group(n=15).The nocturnal duodenogastric bile reflux and gastric pH were significantly decreased after domperidone treatment(P=0.015,0.021).The severity score of nocturnal dyspeptic symptoms was also significantly decreased after domperidone treatment (P=0.010,0.015,0.026),which was positively correlated with the reduced nocturnal bile reflux or gastric pH(r=0.736,0.784,0.753 or r=0.679,0.715,0.697, P=0.039,0.036,0.037 or P=0.043,0.039,0.040). CONCLUSION:A subgroup of Chinese FD patients show overt nocturnal dyspeptic symptoms,which may be correlated with the excessive nocturnal duodenogastric bile reflux.Domperidone therapy can alleviate these symptoms. A: To investigate the incidence of nocturnal dyspeptic symptoms in patients with functional dyspepsia (FD) and whether prokinetic drugs can alleviate them. METHODS: Eighty-five consecutive Chinese patients with FD were included in this study. One week after single-blinded placebo run -in treatment, baseline nocturnal intragastric pH, bile reflux and nocturnal dyspeptic symptoms of eligible patients, including epigastric pain or discomfort, abdominal distention and belching, were investigated with questionnaires. Patients exhibiting nocturnal dyspeptic symptoms were randomly and double-blindly assigned to domperidone group RESULTS: Of the 85 FD patients, 2 females without nocturnal symptoms, who responded to placebo run-in treatment, were excluded from the study, 30 (36.1 %) drawings nocturnal dyspeptic symptoms with increased duodenogastric bile reflux time (intragastric biliru bin absorbance> 0.14) and mean gastric pH (confirming the existence of bile reflux) (P = 0.021, 0.023) at night were included in the study. Of these 30 patients, 21 (70%) had overt nocturnal duodenogastric bile reflux, which The 30 patients were allocated to domperidone group or placebo group (n = 15). The nocturnal duodenogastric bile reflux and gastric pH were significantly decreased after domperidone treatment (P = 0.015, 0.021). The severity score of nocturnal dyspeptic symptoms was also significantly decreased after domperidone treatment (P = 0.010,0.015,0.026), which was positively correlated with the reduced nocturnal bile reflux or gastric pH (r = 0.736,0.784,0.753 or r = 0.679,0.715,0.697, P = 0.039,0.036,0.037 or P = 0.043,0.039,0.040) CONCLUSION: A subgroup of Chinese FD patients show overt nocturnal dyspeptic symptoms, which may be correlated with the excessive nocturnal duodenogastric bile reflux.Domperidone therapy can alleviate these symptoms.