What causes a diverticula to form in the colon?

Diverticula formation in the colon is primarily due to the herniation of the mucosa through weak points in the colon wall, which is precisely what the correct answer describes. As individuals age, the colon undergoes changes that can lead to increased pressure within the intestinal lumen. This pressure, coupled with the presence of weakened areas in the colon wall, typically at sites where blood vessels penetrate, can result in small pouches (diverticula) pushing outward.

The formation of diverticula is more common in certain populations, particularly those with low fiber diets, as a lack of dietary fiber increases the need for the colon to contract more forcefully in order to move stool through, thus raising the pressure within the colon. Over time, this leads to protrusions of the mucosa through the muscular layer of the wall, forming the diverticula.

Other choices involve processes that do not directly pertain to the mechanism of diverticula formation. For example, while muscle tissue or inflammation may occur in the colon, they do not specifically describe the herniation of mucosa, which is critical in understanding how diverticula actually form.