The resumption of bodily activity on rising in the morning is one of the important means by which the bowels are made to act with regularity, by stimulating the colon to empty a portion of its contents into the rectum. When the hours of sleep are irregular, and especially when insufficient time is devoted to sleep, this physiological stimulus is lacking, and constipation may be one of the evil consequences resulting. Loss of sleep causes loss of tone in the intestinal muscles, as well as of general muscular tone, and also lack of appetite, thus diminishing the normal stimuli to bowel movement, and so easily leading to constipation. Even when the bowels do not move soon after rising, the stimulus of rising after a good night's rest at least aids in the filling of the pelvic loop, which then only requires the stimulus of breakfast to cause a normal bowel action. Regularity of sleep is almost or quite as necessary for regular bowel movement as is regularity of meals.
A child does not have to be taught to breathe. It breathes instinctively and hence correctly, for all instinctive movements are physiologically and hence correctly performed. But the breathing muscles are voluntary muscles, and hence may be controlled by the will. This fact permits modifications of the act of breathing, which may or may not be physiological. Unfortunately, the conditions of civilized life are such as lead to serious perversions of the breathing process. Normally, when air is inhaled the whole chest is enlarged, but the chief movement is at the lower sides of the chest. This broadening of the chest at its lowest part stretches the diaphragm and thus gives it an opportunity to exert its greatest force. Its form being arched, this is highly important. If its ends are held in place, the top of the arch can descend only a little, and while breathing is ineffective, the lungs being imperfectly expanded, the compression of the abdominal organs is equally inefficient. The diaphragm, it must be remembered, is a double acting pump. It creates a suction in the chest, while at the same time it produces pressure in the abdomen. If its work is imperfectly done in one direction, it fails equally in the other.
The compressing movements produced by the diaphragm at each inspiration are, when efficient, of great service in assisting the movements of the food along the alimentary tube. Acting upon the stomach, which lies just beneath it, the diaphragm churns the food and aids in pushing it along into the intestine. Acting upon the colon, which on the left side lies in contact with it, the diaphragm renders great assistance in helping to push the food along toward the rectum.
But it is especially in the act of defecation that the action of the diaphragm is important. The very first step in the process of unloading the bowel is in the sinking of the colon by a very deep breath. If the sides of the chest are compressed by belts or a corset, so that they cannot expand, the diaphragm cannot descend more than a short distance, and its action is inefficient As a result, the fecal matters stored up in the descending and pelvic colon are not pushed onward to the rectum, and the bowel is only partially emptied. Thorough natural bowel movement is not possible without free and vigorous movement of the diaphragm.
So, too, if the diaphragm is weak because of ha-bitual shallow breathing, the result of a bad position in sitting at work or study, the same result follows. A position which hampers the movements of the chest thus leads to constipation.
The ordinary house chair, especially the rocking chair and easy chairs in general, train the body in unhealthy attitudes and compel shallow breathing. When the chest is depressed, as when sitting in a hollow-backed chair, the abdominal muscles are relaxed, and the diaphragm cannot act well. There can be no compression of the abdominal viscera without a tense condition of the abdominal muscles. In most constipated persons these muscles are so relaxed and flabby that they render little service. The colon in such cases is compressed so feebly in defecation that it is never properly emptied except when the stools are made fluid by a laxative or by an enema.
When, on the other hand, the chest is raised, as shown in the accompanying cut, the abdominal muscles are stretched, they are thus made tense, and the colon is kept under constant pressure, by which its contents are moved along at the proper rate; and when defecation occurs, these tense, well-developed muscles are ready to do their necessary part of the work.
Probably the majority of sedentary men and most civilizd women spend the greater part of their lives under conditions which induce imperfect breathing and lead to weakness of the abdominal muscles, and so to constipation.
When we consider how universal among civilized women is the practice of compressing the waist by corsets or bands, we find a ready explanation of the fact that four-fifths of them suffer all their lives from constipation, while a large proportion suffer more or less from disorders peculiar to their sex which are by many supposed to be a necessary burden laid upon them, and an inevitable consequence of femininity but are really due to causes which might be easily avoided.