Diverticulosis, otherwise known as "diverticular disease", is the condition of having diverticula in the large colon which are outpocketings of the colon through weaknesses in the colon wall.

Constipation is the most common cause of diverticulosis. Increased intra-colonic pressure secondary to the constipation leads to weaknesses in the colon walls giving way to diverticula.

Infection of a diverticulum can result in diverticulitis.