[The changes of electrogastrogram and gastrointestinal pressure following cholecystectomy]

To investigate the mechanism and pathophysiological changes after abdominal surgery.

Twenty-two patients after cholecystectomy were selected to perform cutaneous electrogastrography (EGG) at least one hour before operation, and the first, the second and the third day after operation respectively. On the operative and postoperative days, gastroduodenojejunal manometry was performed in 17 of the 2 patients.

The percentage of EGG normal frequency on the operative day was obviously lower than that on the preoperative day (P < 0.001), and the percentage of bradygastria on the operative day was obviously higher than that on the preoperative day (P < 0.01). The postoperative EGG amplitude was obviously lower than the preoperative one (P < 0.001), and did not recover after three days. The phase III of the migrating motor complex (MMC) appeared within 24 hours after operation, and first appeared at the duodenum. MMC III was most vigorous at the duodenum in recording period, and was less at the antrum. The contractile power and the area of MMC III at antrum after operation were obviously lower than at duodenum and upper jejunum (P < 0.01). On the third day after operation, the contractile power was lower than normal (P < 0.01).

Gastrointestinal motility dysfunction after cholecystectomy is related to EGG amplitude, and not to EGG frequency. The recovery of antrum MMC III is later than that of small bowl, resulting in delayed gastric emptying. The MMC III of small bowl resums in early period after abdominal surgery. Postoperative ileum is due the decrease of MMC III contractile power and the area after abdominal surgery, which represent the ability of gastrointestinal contraction.