[Pathogenesis and pathophysiology of sigmoid diverticulitis].

The sigmoid colon is the part of the large intestine which is most commonly involved in diverticular disease due to its anatomical properties. True diverticula containing all layers of the colonic wall are rare. The majority of diverticula found are pseudodiverticula. They are herniations of mucosa and submucosa through clefts in the colonic muscle layers as a result of morphologic changes of the colonic wall and an imbalance between the intraluminal pressure and the pressure in the abdominal cavity. Microperforations of the tip of the diverticula are an important factor leading to inflammation and symptomatic disease.