Revised Concepts on Diverticular Disease of the Colon

DIVERTICULOSIS of the colon is a common condition in elderly people. The serious complications, usually termed diverticulitis clinically, have stimulated early radiologic diagnosis and surgical intervention. It seems, however, that the roentgen diagnosis, particularly of “chronic diverticulitis,” has been made too often. We as well as others (1, 2), have noted the remarkable absence of inflammation in a considerable number of colons resected because of this diagnosis. In a previous paper (1) it was shown that in these instances the distortions are often secondary either to massive outpouching of numerous mucosal hernias, “simple massive diverticulosis,” or primarily caused by persistent contraction of the muscularis propria, which we have postulated to be the morphologic end-stage of the spastic colon syndrome, therefore “diverticulosis associated with spastic colon.” The dramatic clinical manifestations of so-called acute diverticulitis are well known. The underlying pathogenic mechanisms, however, are still poorly understood, resulting in misinterpretation of radiologic findings. In a separate study dealing with the pathologic findings in the surgically resected specimens (3), we have observed that the inflammatory complications of clinical significance in diverticulosis were secondary to the rupture of a diverticulum in most, if not all, of the cases. The inflammation was peridiverticular or paracolic. These findings occurred in 65 per cent of the surgical specimens in our series. In 10 per cent, there was true acute diverticulitis with inflammation or ulceration limited to the diverticular lining. Although this type of diverticulitis occurs probably quite frequently, in view of the rather common finding of a slight degree of lymphocytic reaction and fibrosis in the peridiverticular tissue, its clinical significance is questionable, except for the rare instances of massive hemorrhage. Muscular distortion alone accounted for the remaining cases, or 25 per cent. It is the purpose of this paper to present the roentgen observations, to correlate them with the pathologic findings, and to support the thesis that perforation of a diverticulum is the common substratum of the clinical entity of acute diverticulitis. Representative instances demonstrating various aspects of radiologic manifestations, selected from numerous observations, will be presented in a progressive fashion. Observations and Comments 1. Limited Perforation of a Diverticulum, with Serial Observations on the Rupture of a Single Diverticulum A 65-year-old man was seized by an attack of severe pain with deep tenderness in the left lower abdomen without any other local or systemic manifestations.