Chapter 7. Diverticular Disease

“Constipation makes the muscles strain to move stool that is too hard. It is the main cause of increased pressure in the colon. This excess pressure might cause the weak spots in the colon to bulge out and become diverticula.”
Diverticulosis and Diverticulitis; National Institutes of Health [1]

If evolution had anticipated today’s dietary dogma and lifestyle, it would have designed our large intestines very differently. The colon’s pouch-like architecture is the reason behind the existence of diverticulosis, a condition where the haustrum (colonic bulges) protrudes further outward between the teniae (ribbon-like muscles), and forms sacs known as diverticula (plural from the Latin “a turn aside”).

The colon’s original architecture was perfect for hunter-savages, whose lifelong diet was virtually fiber-free. But it’s proved disastrous for Westerners, who’s diet is loaded with fiber from the moment they start chewing. According to The National Institutes of Health:

Based on the U.S. Census 2000, “half of all people over the age of 60” translates into 23 million victims of diverticular disease. Once you factor in people under sixty and the undiagnosed, just as with hemorrhoidal disease the actual number is much greater.

Diverticulosis starts developing during the latent stage of fiber-related constipation which, as you may recall, is primarily characterized by straining, hemorrhoids, and type 1–3 large stools on the Bristol Stool Form Scale. The smaller diverticula range in diameter from 3 mm to 3 cm, and are usually multiple. The ones that are really large are most likely single (the singular is diverticulum), and range in diameter from 3 to 15 cm. When fiber-laden fecesget “diverted” into diverticula, they tend to get lodged there, and then lump together and harden up.

Diverticulosis can be reliably seen and diagnosed by radiography (X-ray, nuclear scans[3]) or colonoscopy long before most patients experience any symptoms. Overall, smaller diverticula are harmless, as long as feces remain small, soft, and moist, because fecal matter with these properties won’t get trapped inside small cre­vices. But when feces are continuously large, hard, and dense, they may keep even tiny diverticula clogged indefinitely for the same reasons a tight cork keeps liquid inside a vessel turned upside down, even if the neck has multiple crevices on the inside.

As more and more fecal matter gets jam-packed inside each diverticulum, they may enlarge further by the sheer force of outward pressure. Eventually, the epithelium inside one or more diverticulum gets lacerated and infected. The infection may cause inflammation, ulceration, rectal bleeding, excruciating pain, and/or the perforation of the colon wall—collectively called diverticulitis.

Besides fiber, other factors and conditions typical for the latent stage of constipation contribute to the development of diverticular disease: