[Anatomy and pathogenesis of diverticular disease].

BACKGROUND: Although diverticular disease is one of the most frequent gastrointestinal disorders the pathogenesis is not yet sufficiently clarified.
OBJECTIVES: The aim is to define the anatomy and pathogenesis of diverticular disease considering the risk factors and description of structural and functional alterations of the bowel wall.
METHODS: This article gives an appraisal of the literature, presentation and evaluation of classical etiological factors, analysis and discussion of novel pathogenetic concepts.
RESULTS: Colonic diverticulosis is defined as an acquired out-pouching of multiple and initially asymptomatic pseudodiverticula through muscular gaps in the colon wall. Diverticular disease is characterized by diverticular bleeding and/or inflammatory processes (diverticulitis) with corresponding complications (e.g. abscess formation, fistula, covered and open perforation, peritonitis and stenosis). Risk factors for diverticular disease include increasing age, genetic predisposition, congenital connective tissue diseases, low fiber diet, high meat consumption and pronounced overweight. Alterations of connective tissue cause a weakening of preformed exit sites of diverticula and rigidity of the bowel wall with reduced flexibility. It is assumed that intestinal innervation disorders and structural alterations of the musculature induce abnormal contractile patterns with increased intraluminal pressure, thereby promoting the development of diverticula. Moreover, an increased release of pain-mediating neurotransmitters is considered to be responsible for persistent pain in chronic diverticular disease.
CONCLUSIONS: According to the present data the pathogenesis of diverticular disease cannot be attributed to a single factor but should be considered as a multifactorial event.