Autoimmune diseases involving the gastrointestinal tract: clinical patterns, imaging spectrum, and complications.

Autoimmune diseases frequently involve the gastrointestinal (GI) tract and can present with nonspecific symptoms that delay diagnosis. Their manifestations range from subtle motility disturbances to life-threatening ischemia, perforation, or obstruction. Advances in cross-sectional imaging have reshaped the evaluation of autoimmune and vasculitic diseases, allowing recognition of mural, mesenteric, and vascular signatures that reflect the underlying pathophysiology. Integrating these findings with clinical and serologic data remains essential to narrow differential diagnoses and to guide early management. This review adopts a pattern-based framework to classify autoimmune diseases with GI involvement into three categories: primary autoimmune GI diseases (celiac disease, Crohn's disease, and ulcerative colitis); systemic autoimmune diseases with secondary GI involvement (systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome); and other autoimmune or vasculitic entities with occasional GI manifestations (polyarteritis nodosa, IgA vasculitis, Behçet disease, Takayasu arteritis, dermatomyositis, and IgG4-related disease). Understanding these imaging patterns within the clinical and serologic context enhances diagnostic confidence, facilitates early recognition of complications, and promotes multidisciplinary collaboration in the management of autoimmune gastrointestinal diseases.