False diverticulum or pseudodiverticulum: type of diverticulum that involves only the mucosa and submucosa and does not contain muscular layer or adventitia.
Most common type of gastrointestinal diverticula
Typically acquired
Localized particularly in the sigmoid colon
The sigmoid colon is the section of the colon with the smallest diameter. Due to the narrow passage, intraluminal pressure is highest in the sigmoid colon, which promotes the formation of diverticula.
Diverticulosis: the presence of multiple colonic diverticula without evidence of infection
Epidemiology
In the US, ∼ 50% of individuals > 60 years have diverticulosis
Etiology
Caused mainly by lifestyle and environmental factors
Diet (low-fiber, rich in fat and red meat)
May lead to constipation
Obesity
Low physical activity
Pathophysiology
Increased intraluminal pressure, e.g., due to chronic constipation
Weakness of the intestinal wall
Age-related loss of elasticity of the connective tissue
Physiological gaps in the intestinal wall, which occur where blood vessels penetrate, predispose to protrusion and herniation of intestinal mucosa and submucosa.