Effect of rectal distention and feeding on cecal tone in pigs

The effects of eating and rectal distention on cecal tone were evaluated. Cecal tone was measured using a computer-controlled barostat in four female 30 to 40 kg Yucatan Micropigs fitted with cecal fistulas. Each pig underwent two separate trials of pre and postprandial measurements of cecal tone, either with or without continuous rectal distention with a 30 ml water-filled balloon. Cecal tone was measured 10 min prior to, during, and 10 min following a high-fat (60%) liquid meal (473 ml). Cecal tone significantly increased (intrabag volume decreased) after feeding (119.6 ± 9.1 ml vs. 81.2 ± 7.9 ml; p = 0.008). Rectal distention tended to reduce the postprandial change in cecal tone (142.8 ± 11.5 vs. 130.9 ± 12.6 ml; p = 0.196). There was also a strong tendency for cecal volumes to be higher (decreased tone) with rectal distention preprandially (142.8 ± 11.5 ml vs. 119.6 ± 9.1 ml; p = 0.024). Nutrient ingestion significantly increased cecal tone and rectal distention abolished this effect. These findings may indicate a regulatory pathway that allows additional storage of fecal material in the event that the output of the system is disturbed.