A total of 722 surgical cases of Meckel's diverticulum was encountered at the Mayo Clinic from 1906 through 1960. In 560 cases it was an incidental finding in the course of other surgical procedures, while in 162 cases the diverticulum was the specific cause for surgical intervention. The symptomatic diverticula presented in the following manner: persistent omphalomesenteric fistula (8), component of a hernial sac (9), intussusception (15), inflammation (29), intestinal obstruction excluding intussusception (28), hemorrhage (63), and neoplasm (10). The symptoms of diseased diverticulum are not specific to it alone but rather are characteristic of the pathologic process occurring in it. For this reason, Meckel's diverticulum must be considered as a possible cause of any intra-abdominal condition which cannot be readily diagnosed.MECKEL' S DIVERTICULUM is an anatomic entity whose clinical and surgical manage¬ ment has intrigued physicians for more than 150 years. Numerous papers have appeared detailing each of the ways the symptomatic diverticulum makes its presence known. This presentation is an attempt to describe the over-all experience of the Mayo Clinic with this interesting problem.The first recorded description of Meckel's diver¬ ticulum has been attributed to Fabricius Hildanus ' in 1598. In the ensuing years the literature on this subject was enriched by the writings of Lavater,2 Ruysch,:1 and Littre '; however, it remained for Meckel5 to establish this condition on sound ana¬ tomic and embryologie grounds in numerous arti¬ cles appearing between 1808 and 1820.The omphalomesenteric duct connects the yolk sac with the intestinal tract at the junction of the foregut and hindgut during early embryonic life and is normally completely obliterated by the fifth to seventh week of gestation. Failure of complete obliteration may result in an omphalomesenteric fistula, Meckel's diverticulum, an enterocyst, or a fibrous band running from the small intestine to either the adjacent bowel or the umbilicus. Originally, paired omphalomesenteric arteries and veins were present. The left artery and right vein normally are obliterated, but the right artery is incorporated into the superior mesenteric artery while the left vein forms part of the portal vein.All of the surgical cases of Meckel's diverticulum encountered from 1906 through 1960 at the Mayo Clinic were reviewed and classified into 2 groups depending on whether the diverticulum was an incidental surgical finding or whether it was the seat of surgical disease. The latter category was then subdivided into the various pathologic condi¬ tions encountered at operation. A total of 722 cases was reviewed; these form the basis of this paper. Incidental Surgical Finding.-A total of 560 diverticula in this series comprised the incidental sur¬ gical findings, 402 being excised and 158 being left in situ. The main reason for leaving the diverticu¬ lum in place was that wide-mouthed diverticula were not deemed to be potential sources of danger, and thus their removal would add...