Segmental colitis associated with diverticulosis: is it the coexistence of colonic diverticulosis and inflammatory bowel disease?

Segmental colitis associated with diverticulosis (SCAD) is an inflammatory process that affects colonic luminal mucosa in segments that are also affected by diverticulosis. Its prevalence varies between 1.15% and 11.4% amongst those suffering from diverticular disease (DD). Being closely associated with DD, it is slightly commoner in males and usually presents in the sixth decade of life. Although the exact pathogenesis of SCAD is unknown, it is probably heterogeneous and includes mechanisms that also play a part in inflammatory bowel disease (IBD). The clinical presentation is non-specific and similar to that of other pathologies involving the sigmoid colon, and its diagnosis is based on endoscopic findings in correlation with histology. Currently, there are no guidelines for its management, which is usually based on the administration of salicylates and antibiotics, with surgery being reserved for refractory cases. The rarity of SCAD may be multifactorial: whereas milder forms go undiagnosed or are attributed to DD, more severe forms can be misdiagnosed as IBD. This latter distinction is an important one to make, since SCAD and IBD differ as regards their natural history and prognosis, while very often no long-term medications are required in SCAD.