Revised Concepts on Diverticular Disease of the Colon

Diverticulosis and diverticulitis of the colon are common occurrences of advanced age. Carroll (1), Welch (2), and McCune et al. (3) have estimated that in about 6 million of the 60 million persons in the United States who are over forty years of age, diverticulosis will develop. Of those with diverticulosis, about 20 per cent (1.2 million) will suffer from diverticulitis requiring proper diagnosis and treatment. The older the patients, the more seriously are they afflicted with complications. Despite the frequency of this disorder and the improved knowledge of its management, there still exists considerable confusion about the morbid anatomy, pathogenesis, course, and complications, particularly in the differentiation between diverticulosis and diverticulitis. Although diverticula of the colon had been known to pathologists for a long time, it was Graser who in 1898 (4) elevated them from an anatomic curiosity to clinical reality by his observation that they were found, both topographically and pathomechanically, in the center of inflammatory masses about the sigmoid. Brewer (5), Mayo (6), and others confirmed these findings. It was not until 1914, however, that the concept of “diverticulosis” was developed when radiologists such as De-Quervain (7), Case (8), and Carman (9) observed, with increasing frequency, asymptomatic diverticula of the left colon. Since surgical intervention is often required, the distinction of diverticulosis, usually of little clinical significance, from the severe inflammatory changes, now called “diverticulitis,” has become important. An extensive bibliography over three decades shows the groping for a clear answer by radiologists, internists, and surgeons. Goulard and Hampton (10), and Wolf, Khilnani and Marshak (11), in careful comparative studies, brought new light and a solid foundation to our understanding. Quite recently Morson (12) and Williams (13) called attention to the gross changes in the muscularis of the colon in these and related conditions. Many aspects of diverticular disease of the colon, however, remain poorly understood and misinterpreted. For a number of years, we have studied this disorder by close roentgen-pathologic . This communication presents our findings and concepts of diverticulosis of the colon and offers our interpretations of the morphologic alterations commonly observed in this condition. The problem of complications of diverticulosis such as inflammation and perforation, usually summarized as diverticulitis, will be dealt with in a separate article. Methods and Material Many years of clinical, roentgenologic, and pathologic experience in a hospital with active medical and surgical services form the core of this study and the basis of the concepts adopted.