Final answer:
A previous theory on diverticulitis that is no longer valid is the belief that eating nuts, seeds, and popcorn can cause diverticular disease. Instead, the current understanding is that diverticular disease is primarily caused by a low-fiber diet. Another outdated theory was that stress or psychological factors could cause diverticulitis.
Step-by-step explanation:
A previous theory on diverticulitis that is no longer valid is the belief that eating nuts, seeds, and popcorn can cause diverticular disease. It was commonly believed that these foods could get trapped in the diverticula and lead to inflammation and infection. However, research has shown that there is no evidence to support this theory.
Instead, the current understanding is that diverticular disease is primarily caused by a low-fiber diet. When people don't consume enough fiber, their stools become harder and more difficult to pass. This puts extra pressure on the colon, leading to the formation of diverticula and an increased risk of diverticulitis.
Another outdated theory was that stress or psychological factors could cause diverticulitis. However, there is no scientific evidence to support this claim. Diverticulitis is primarily a physical condition caused by inflammation and infection of the diverticula.