Your Table of Contents Part 3 - Sphincter in Food Digestion
The bile formed by the liver passes down the bile duct, encounters the closed valve, and is thus prevented at the moment from passing into the intestine. It backs up into what is known as the gall bladder. However, the moment the acid content of the stomach gets into the intestine, it relaxes this little valve or sphincter and the bile, itself a digestive juice, flows out of the gall bladder into the intestine and automatically mingles with the food undergoing digestion.
The onward rhythmic urge of peristalsis thus acts as a conveyor belt for the food substances along the food digestion canal subject to the normal periods of delay and which permit not only digestion but as these products of digestion reach a suitable point of simplicity, it also permits their absorption.
Finally, of course, the food mass gets to the very lower end of the intestine. Here there is another sphincter or valve which normally holds the material in the intestine until the time is right for it to move on. This particular sphincter, however, serves not only to delay the food mass until it is thoroughly digested and partially absorbed, but it also serves to keep the material which has been passed into the colon from backing up into the small intestine. It is known as the ileocecal valve.
Not infrequently in cases where we have diseased conditions in the food digestion canal, material does regurgitate or “back up” from the colon into the small intestine. In time this gives distinct evidences of disorder in the form of grumbling noises and excessive gas in the abdomen.
Still further on, there is another band of circular fibers which serves to keep in the colon food material, which by now is largely food residue. We have this poorly defined sphincter right where the lower colon joins the rectum. While the actual evidence of this sphincter has been denied, those of us who specialize in intestinal ailments see abundant evidence of its existence. It is, indeed, the cause of many cases in what appears to be intractable constipation, since it causes the prolonged retention in the colon of waste matter that should have been passed into the rectum and on out. The fact that this is the most frequent location of cancer of the colon gives important significance to the location of this sphincter.
Finally, we come to the sphincter or valve best known to people in general. It is the anal sphincter and it controls the passage of the food waste material or bowel movement out of the rectum. It is the only sphincter in the food digestion canal over which we have control. This fact has given rise to more trouble for the human digestive system than any other single fact of life. This is so chiefly because of the abuse man has made of the privilege of controlling his bowels. Civilized life imposes certain understandable but nevertheless harmful restraints on this most important of all functions, excretion. Instead of restricting this restraint, however, merely to that demanded by polite society, many people extend the restriction by denying Nature’s Call whenever they are “too busy” or too lazy to respond. By so doing, they not only thwart the normal act of excretion, but they reflexly throw out of tune the normal rhythm of the upper parts of the food digestion canal.
Depending on how often they sin against Nature in this manner, the effects progress from temporary disturbance of the lower bowel to a point where the proper functioning of the whole food digestion canal and even the total health of the person is seriously in jeopardy. A high price, indeed, to pay for the privilege of control. And a sure proof of the wisdom of the great Maker that He permitted control of so few other vital functions to the mind of man.
Did you ever hear a person say they were “tied up in knots”? Well, that is probably how they felt and the description is pretty nearly true. The knots occur where these valves are, for upon their proper functioning depends whether life along the alimentary canal is going to be healthy and pleasant or not!, no pun intended.
