The purpose of the present study is to evaluate the role of the x-ray examination in the management of patients with intestinal obstruction. In recent years the radiologist's opportunity in this field has been extended by the introduction and increasing use of the Miller-Abbott tube. It is therefore proposed to consider in some detail the use of this tube, with particular reference to the radiological examination. Brief reference will also be made to the over-all improvement in the operative management as a result of the introduction of this surgical adjunct, and pertinent figures will be cited from a series of cases of small intestinal obstruction treated in the Hospital of the University of Pennsylvania over a five-year period. With the onset of intestinal obstruction, many physiological changes ensue. A thorough understanding of these changes and their variation with the location, degree, duration, and nature of the occlusion are essential if the radiologist is to have a thorough understanding of the surgical problem and thus contribute to its solution. This phase of the subject has been amply covered by Wangensteen (41) and space need not be given it here. The clinical features are likewise well known, and a brief summary of these will suffice. Except in high obstruction, intestinal colic is the prime manifestation of intestinal occlusion, though in late cases bowel activity may be so reduced that clear-cut colic is recognized with difficulty. Distention invariably results if the obstruction is untreated. It may not, however, be clinically evident in early cases, and it is in the demonstration of its presence at this stage that the x-ray is of particular value. Vomiting is a prompt and persistent symptom of high obstruction and appears in most cases of small intestinal occlusion. It may be entirely absent in closed-loop obstructions of the colon or may be infrequent and of reflex origin. Persistent tenderness, fever, and leukocytosis are suggestive of strangulation. It is particularly important that this possibility be considered, since only if it can be ruled out is it justifiable to resort to suction drainage. Roentgen Diagnosis While the clinical diagnosis of intestinal obstruction is often adequate, the roentgen examination offers valuable confirmatory evidence and in many cases is useful in determining the location of the obstruction as well. Without the administration of barium, it is rarely possible to come to any conclusion as to the etiology, but it is never advisable to resort to the use of barium except by enema. The roentgen examination is best begun with fluoroscopy of the chest or, if this is deemed too distressing to the patient, roentgenography in the upright position. This may disclose possible pulmonary disease, establishing the distention as of reflex origin rather than due to actual obstruction, or it may reveal conditions directly related to an obstructive lesion, as for example the presence of metastatic deposits.