The development of colonic diverticulum is thought to be a result of raised intraluminal colonic pressures. The sigmoid colon has the smallest diameter of any portion of the colon, and therefore the portion which would be expected to have the highest intraluminal pressure according to the laws of Laplace. The postulate that low dietary fiber, particularly non-soluble fiber (also known in older parlance as "roughage") predisposes individuals to diverticular disease is supported within the medical literature.
It is thought that mechanical blockage of a diverticulum, possibly by a piece of feces, leads to infection of the diverticulum.
