The transverse colon is the longest and most movable part of the colon. It crosses the abdomen from the ascending colon at the hepatic or right colic flexure with a downward convexity to the descending colon where it curves sharply on itself beneath the lower end of the spleen forming the splenic or left colic flexure. In its course, it describes an arch, the concavity of which is directed backward and a little upward. Toward its splenic end there is often an abrupt U-shaped curve which may descend lower than the main curve.