Prolonged ambulatory monitoring of colonic motor activity in the pig

The aim of this study was to develop a chronic model suitable for repeated, long-term studies of the interaction of behavior and colonic function in unrestrained pigs. Cecostomies were created in three 20-30 kg micropigs under general anesthesia. Fistulas were created by suturing the bowel to the abdominal wall. Recordings were made by passing a small (8F) solid-state pressure transducer through the fistula into the proximal bowel and connecting it to a battery-operated data logger worn in a vest on the pig's back. Cecostomies have remained patent and trouble-free for over 18 months. No serious infections have occurred. Preliminary data from a total of thirteen 24-h recording sessions showed 54% of all contractile activity to be in the 2-4 cpm frequency range. Increased motility was seen following meals and upon morning awakening. Motility was minimal during the night. Infrequent (10.31 +/- 2.05/24 h; mean +/- SD) propagated contractions were also noted. These contractions were generally of low amplitude (33.24 +/- 3.81 mmHg). These techniques allow prolonged, intraluminal recordings to be made from the colon of the unrestrained pig.