A Comprehensive Review of Infectious Granulomatous Diseases of the Gastrointestinal Tract.

A granuloma is defined as a localized inflammatory reaction or a hypersensitive response to a nondegradable product leading to an organized collection of epithelioid histiocytes. Etiologies of granulomatous disorders can be divided into two broad categories: infectious and noninfectious (autoimmune conditions, toxins, etc.) causes. The endless list of causalities may prove challenging for gastroenterologists and pathologists to formulate a list of clearly defined differentials. This is true when distinguishing these etiologies based on various clinical presentations and endoscopic and histological findings. We aim to provide a comprehensive review of some of the frequent and rare infectious granulomatous diseases of the gastrointestinal tract documented in the literature to date. We provide an overview of each infectious pathology with an emphasis on epidemiology, clinical presentation, and endoscopic and histologic findings, in addition to treatment.