Intestinal Obstruction: Further Experiences in the Use of Flat Abdominal Films

Abstract

In 1937 we reported a series of cases of intestinal obstruction diagnosed with the aid of flat films of the abdomen. The experience gained in the first series proved of considerable value in estimating the significance of a distended abdomen, and we have continued our study for the past seven years. While we have nothing startling to report, we feel that certain impressions and experiences should be recorded. Perhaps a few statements should be made as to the findings which enable one to make a diagnosis of mechanical obstruction by the use of flat films. A gas bubble is normally present in the stomach, and gas in varying amounts in the colon. The small bowel, on the other hand, shows little or no gas when normal peristaltic movements are present. In the presence of abnormal stasis, however, gas begins to collect proximal to the point of stasis and quickly becomes visible on the roentgen film. Gas in the colon normally is derived from small bowel contents. When these contents fail to reach the large bowel in sufficient amounts, the colon gas is diminished and in severe cases disappears. These are the physiological facts upon which is based the roentgenographic diagnosis of obstruction. The roentgenologist, therefore, when confronted by a film, must determine: (1) Is there gas in the intestinal tract? (2) Is it in the colon or in the small bowel or both? (3) If in both, what is the relative amount in each? With these three questions answered, a diagnosis can readily be made and a shrewd guess can be hazarded as to the location of the obstruction. The real problem lies in the second question, as the utmost care may at times be necessary to differentiate between small and large bowel. Since this differentiation is all-important for a diagnosis, considerable effort and study should be devoted to its accomplishment. We have found that a repeat examination, sometimes within an hour, is the greatest single aid in solving this problem. Certainly, we must admit, cases are encountered in which it is extremely difficult to distinguish between the distended Kerkring folds of the small bowel and the normal haustral markings of the large bowel. Occasionally one is satisfied that gas is present in both the small and large bowel. This could be due to a reflex paralytic ileus from shock, as from renal colic, to gastrointestinal pneumatosis, peritonitis, or partial mechanical intestinal obstruction. If treatment is to be instituted at a favorable time, differentiation of these conditions is of prime importance. It can be made only after careful study and repeated examinations. One must determine whether the small bowel is distended more than the large bowel. If both are equally distended (not necessarily to the same size; it is a question of percentages), paralytic ileus is considered first. If the small bowel attains the size of the colon in the film, partial mechanical obstruction is diagnosed.