Rheumatoid arthritis (RA) is a systemic autoimmune disease primarily affecting the joints but also involving extra articular manifestations. One significant extra-articular feature is the alteration in the mucosal lining of the small intestine. This study investigates the functional changes in the small intestine's mucosa in RA patients, exploring potential implications for disease management and patient outcomes. The research employs histological and immunohistochemical techniques to evaluate mucosal integrity and functionality, with findings indicating significant alterations in mucosal structure and function in RA patients. These changes may contribute to gastrointestinal symptoms and impact overall health in RA.