[7] Diverticular disease was found associated with a higher risk of left sided colon cancer.

When symptoms do appear in a person over 40 years of age it is important to obtain medical advice and exclude more dangerous conditions such as cancer of the colon or rectum.

[13][14][15][16] Segmental colitis associated with diverticulosis (SCAD) is a condition characterized by localized inflammation of the colon between diverticula (interdiverticular mucosa) while sparing the diverticular orifices.

SCAD may lead to abdominal pain, especially in the left lower quadrant, intermittent rectal bleeding, and chronic diarrhea.

[1] Another theory suggests the degeneration of glial neurons in the myenteric plexus and the interstitial cells of Cajal lead to slowed intestinal movement and consequently fecal content exerts increased pressure on the colon wall resulting in the formation of diverticula.

[1] Multiple theories have been proposed including genetic susceptibility, diet, intestinal motility, changes in the microbiome, and inflammation.

One leading theory suggests that diverticula form in weakened areas of the colon wall that are subjected to increased pressure.

[2] One study found that nuts and popcorn do not contribute positively or negatively to patients with diverticulosis or diverticular complications.

These complications are often grouped under a single diagnosis of diverticulitis and require skilled medical care of the infection, bleeding and perforation which may include intensive antibiotic treatment, intravenous fluids, and surgery.

[30] A strong case was made by Neil Painter[31] and Adam Smith[32] that a deficiency of dietary fiber is the cause of diverticular disease.

They argued that the colonic muscles needed to contract strongly in order to transmit and expel the small stool associated with a fiber deficient diet.

The increased pressure within the segmented section of the bowel over years gave rise to herniation at the vulnerable point where blood vessels enter the colonic wall.

"The complications of diverticulosis cause considerable morbidity in the United States; health care expenditures for this disorder are estimated to be $2.5 billion per year.