Diurnal variations in the pH of pathological gallbladder bile.

The pH of gallbladder and common duct bile from patients undergoing surgery for cholecystectomy has been measured. The bile was collected and kept anaerobically at 37 degrees C, and the pH measured at 37 degrees C, generally within 30-60 minutes of the bile being taken from the patient. Only data from patients having functioning or poorly-functioning gallbladders were included in the calculations. The pH of common duct bile was always greater than that of the corresponding gallbladder bile, and the data available suggest that it does not vary diurnally. The mean pH of gallbladder bile from patients undergoing their operation at different times during the day shows a diurnal variation, the bile becoming more acidic with time. Furthermore, there is also a diurnal variation in the activity of the acidifying process. Data for the patients suggest this is retarded by sleep, inactivity, or lying down.