Unusual Variations and Atypical Presentations of Diverticulitis.

In this article, we describe four unusual variations of diverticulitis: nonsigmoid colonic diverticulitis, giant colonic diverticulum, segmental colitis associated with diverticulosis, and small bowel diverticulitis. We discuss the epidemiology, presentation, and treatment of these types and how they differ from the presentation of typical sigmoid diverticulitis. We also review unusual presentations of typical sigmoid diverticulitis, including hematogenous liver abscess, necrotizing soft-tissue infection, and genitourinary fistula. Diverticulitis is a heterogeneous disease, and understanding the range of its presentations will facilitate early diagnosis and treatment.