The colon, the second part, extends up through the right lumbar region, and is here called the ascending colon. At the under surface of the right lobe of the liver it bends forwards and to the left, and crosses the abdomen, where it is called the transverse colon. In the left hypochondrium, near the spleen, it again bends downwards and forward, passing down through the left lumbar region, and is called the descending colon ; at the anterior spine of the ilium it bends after the manner of an S, and takes the name of the sigmoid flexure. The intestine then inclines inwards to the middle line, and descends in front of the sacrum, and is called the rectum.

The rectum is 6 or 8 inches long ; when it reaches the middle of the sacrum it follows the curve of that bone and ends in the anus.

The coats of the intestines are the same in number and name as those of the stomach. In the small intestine the transverse folds of the mucous lining are permanent, and are called valvulae conniventes ; they and the intervals between them are covered with little projections called villi. In the centre of each villus is a lacteal.