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| The Surgical Technologist | OCTOBER 2016 452 name due to its S shape (Greek: sigma). The diameter of the sigmoid colon is determined by the amount of waste in the colon. The sigmoid colon can be as small as 2.5 cm in diam- eter when completely empty. The sigmoid colon has a similar cellular makeup as the rest of the colon with some subtle differences. The lining is composed of a mucus membrane that secretes mucus and can also absorb some fluid. The inner layers of the sigmoid colon are composed of a circular muscle and a sheath of longitudinal muscle. Both muscles aid in the movement of waste through the colon, and the longitudinal muscle layer also is responsible for the disposal of waste out of the colon and into the rectum. Fecal waste material can be stored in the sigmoid colon for seven hours or more until new waste material needs to be moved into this area and the waste needs to be expelled. D I V E R T I C U L I T I S The etiology of diverticulitis is not known, but a low fiber diet has proven beneficial. Without fiber to add bulk to the stool, the colon has to work harder to move stool out of the colon. This puts pressure on the weak portions of the colonic wall, where the blood vessels enter and the pressure creates small pouches. One theory is that the stool becomes trapped in these pouches where bacteria grows, which may lead to inflammation and infection. I N D I C A T I O N S F O R S U R G E R Y Most people with diverticulosis remain asymptomatic throughout their lives. Only 10% to 25% develop symptoms and have to seek medical treatment. The most common clinical manifestations include perforation, abscess devel- opment, fistula formation, obstruction and hemorrhage. Other patients may present with non-acute complaints such Credit: James Heilman, MD Diverticulitis in the left lower quadrant