This article is based on an analysis of the immediate and late results in one hundred consecutive cases of acute intestinal obstruction in which operation was performed at the Reading Hospital from August 1925 to August 1933. Intestinal obstruction or ileus is the term used to indicate a stoppage of the fecal current, this condition being secondary to some pathologic process within or without the intestine, which is the primary condition. If the primary condition is mechanical, there is a mechanical obstruction; if it is due to a nervous or toxic influence which paralyzes the intestines, it is a paralytic or adynamic ileus, and if it is due to a spasm or contraction of the intestinal wall, it is dynamic ileus. By far the larger number of instances of obstruction are due to mechanical agents. In the present series the causative factor was mechanical obstruction, and in all the cases