The colon is divided into four parts: the ascending, transverse, descending and sigmoid. The ascending and transverse colon meet at the right hepatic flexure (near the liver). The transverse and descending colon meet at the left splenic flexure (near the spleen).
The large intestine has three bands of longitudinal muscle fibers called taeniae coli. In between the bands the wall of the colon forms saccules called haustra. The three bands start at the base of the appendix, travel the length of the colon and blend into the outer muscle layer of the rectum. The appendix is a hollow tube and contains lymphoid tissue.