Background and study aim: Colonic diverticulosis is a common condition characterized by small pouches (diverticula) in the colon. These pouches can become inflamed or infected, leading to a condition called diverticulitis, or complicated by bleeding and perforation. Data about the utility of fecal calprotectin (FC) in managing colonic diverticular disease (DD) in the Egyptian literature is lacking. Fecal calprotectin (FC) is a protein used as a sensitive marker of colonic inflammation. The current study aims to evaluate the FC levels in different degrees of colonic diverticular disease. Patients and Methods: Three hundred sixty patients, 215 females and 145 males visiting the outpatient clinic of the participating centers were recruited. Patients were endoscope due to various indications All patients were exposed to full history taking, laboratory tests, abdominal CT scan with contrast, and colonoscopy with biopsies together ELISA based FC assay.