Diverticulosis is a common disease affecting the colon, and its etiology is multifactorial. Diverticula, or outpouchings of mucosa and submucosa, form in the wall of the colon, often where the vasa rectal penetrate the muscular layer of the colon wall. Diverticulosis is caused by a complex interplay between dietary and environmental factors, genetics, degenerative changes within the colon, and altered colonic motility. Diverticulitis occurs when diverticula become inflamed and irritated. Genetic susceptibility; environmental influences such as obesity, smoking, or dietary factors; inflammation; and alterations in the gut microbiome work in combination to give rise to diverticulitis.