Nine gallstone patients with normal gallbladder function as assessed by hepatobiliary scintigraphy were included. Fasting and postprandial duodenal motility were studied before and one month after an uncomplicated laparoscopic cholecystectomy. An ambulatory continuous pressure recording was obtained from 5 PM to 8 AM with a sampling frequency of 4 Hz. At 6 PM, the patients received a 1400-kJ standard meal. The size of the bile acid pool after cholecystectomy was measured according to the dilution principle using [C14]cholic acid as the marker. Preoperatively the migrating motor complex (MMC) cycle was 0.48/hr (quartiles 0.42-0.68) compared to 0.68/hr (0.43-0.77) postoperatively. This difference was not significant. An increase in the MMC cycle frequency was observed postoperatively in three patients, and a decrease was seen in four patients. The migration velocity was 5.61 cm/min (4.26-8.01) preoperatively and 7.16 cm/min (4.79-9.71) postoperatively, a difference that was not significant. The time period from meal ingestion to appearance of phase III was 297 min (218-431) at the preoperative examination and 443 min (192-494) at the postoperative examination. This difference was not significant. The size of the bile acid pool after cholecystectomy was 3.68 mmol (2.69-8.47) and was not significantly correlated to the frequency of the MMC cycle or the time period from food ingestion to phase III activity. It is concluded that in gallstone patients with a normally functioning gallbladder, cholecystectomy does not alter duodenal motility, which was not correlated to the size of the bile acid pool.