Diverticulitis

Diverticular disease of the colon is an acquired condition affecting societies that consume a refined, fiber-deficient diet. Consequently, the degree of colonic muscle contraction needed to propel hard, inspissated stools caudally is increased and this, in turn, causes herniation of mucosa through weakened points. These false diverticula are found between the taenia (where there is only the circular muscle layer of the muscularis propria) at the point where the vessels penetrate the bowel wall from the subserosa to the submucosa. Most diverticula are located in the sigmoid colon and do not produce symptoms. Occasionally, a diverticulum will become infected with normal colonic flora as a result of stasis or mucosal abrasion from a fecalith; this sets in motion a cascade of inflammation which may spread either longitudinally within the wall or transmurally into adjacent structures. A patient will then experience left lower quadrant pain. Other conditions which initial produce a similar clinical picture include cancer, ischemic colitis, inflammatory bowel disease, and irritable bowel syndrome.