Motor Activity of the Distal Bowel in Intestinal Obstruction

Abstract

The bowel distal to the point of obstruction is normal anatomically, whereas the proximal bowel exhibits anatomical changes. Alvarez 1 states that most of the motor activities of the stomach and bowel are brought about and regulated largely by the internal pressure due to the presence of food or gas, on which basis an eventual condition of inactivity in the bowel distal to a complete obstruction would appear to be understandable. But the distal bowel has been found to evacuate enemas and transport barium in approximately normal time. In this study an attempt has been made to study the motor activity of the distal segment of the bowel in the presence of simple obstruction. There were 22 dogs obstructed, the point of severance being usually 3 to 5 feet above the ileo-caecal valve. The proximal end was turned in and the distal end anchored to the skin in 8 dogs. In 14 others both ends were inverted.

Small rubber balloons were inserted into the bowel and the contractions of the bowel recorded upon a smoked drum by means of a water manometer. From the distal segment tracings could be obtained through the enterostomy without the employment of anesthesia.

Tracings in the normal bowel show rhythmic contractions occurring about 10 to 15 times per minute. The height of the contraction varies to such an extent in different animals and at different times in the same animals that no numerical average can be adopted for quantitative comparisons. However, tracings of the distal loop resemble closely tracings of the normal bowel studied under similar conditions.

In a comparison of the activity of the proximal and distal loops recorded simultaneously on the same tracing in 13 experiments the greater activity occurred in the proximal loop 5 times, in the distal loop 7 times and in one case (Fig. 2) the greater activity occurred first in the proximal and later in the distal segment.