The etiology, that is, the exciting cause, of the inflammation of the anus, rectum, colon, etc., may date from the time a diaper was placed on the new-born infant. Excoriations of the integument about the anus by the excretions of bowels and bladder indicate that the mucous membrane of anus and rectum demands local remedies, as well as the integument of the buttocks, and that it is not the liver which is at fault. The many applications of the diaper during the period of its use, and the frequently delayed removal at night or during long rides in baby wagons, railway trains or carriages, and during long social visits of the nurse; constipating foods, lack of drinking water, constipating medicines, followed by all sorts of purgatives, etc., are among a few of the direct causes of diseases of the rectum. A child at the age of eighteen months with a healthy rectum is most rare. The ten thousand and one chances for contracting disease of the anus and rectum do not cease with the period of infancy. The child is left pretty much to shift for itself as to regularity of eating and the evacuation of the contents of its bowels, wherein disease has already obtained a foothold. All kinds of foodstuffs, at all hours, with seeds, stones, etc., are poked into its stomach, followed by constipating remedies to quiet inevitable troubles, or brisk purgatives given with the hope of expelling the arrested contents of the bowels. Is it any wonder that ninety-eight persons of adult age out of every hundred suffer more or less from chronic inflammation and ulceration of anus, rectum, sigmoid flexure, colon, or appendix? Traumatic (externally produced) injuries to the mucous membrane of the rectum frequently cause inflammation, and hard pieces of bone, wood, seeds, imbedded in the feces, scratch, cut and bruise the tissues before and during the act of defecation. Cold boards, stones, earth and other substances used as seats may produce inflammation of the rectum. There are many and various causes which may be the means of exciting inflammation of the anus and rectum later in life; but it is the writer's opinion that the cause can be traced back to infancy or early childhood, and that accidents or imprudence in after years merely excite an already-existing chronic inflammation. Piles, fissure, itching pockets, tabs, prolapse, abscesses, fistulæ, etc., are only the outcome and symptoms of a chronic disease which has incubated for fifteen, twenty or more years. None of this list of troubles produces constipation. It is the inflammation located at the middle portion of the rectum and extending into the sigmoid flexure that causes constipation; that protean monster which deranges more lives with nervousness than any other pathological condition to which the flesh of man is heir! CHAPTER II. THE PHYSICS OF DIGESTION AND EGESTION.