CONSTIPATION.
BY W. W. JOHNSTON, M.D.
SYNONYMS.—Costiveness, Fecal retention, Fecal accumulation, Alvine obstruction, Obstipation. Ger. Koprostase, Stuhlverstopfung, Hartleibigkeit, Kothstanung. Fr. Constipation, Paresse du ventre, Échauffement. It. Constipazione. Older synonyms: Constipatio vel obstipatio alvi; Alvus tarda, dura, adstricta; Tarda alvi dejectio; Obstipatio alvarina; Stypsis; Coprostasis (Good).
NATURE AND DEFINITION.—The act of defecation is almost wholly due to the working of an involuntary mechanism which may be set in play by the will, and is in part dominated by it, but which is frequently independent and uncontrolled by volition. Deep inspiration, closure of the glottis, downward pressure of the diaphragm, and contraction of the abdominal muscles are accessory, but not essential, to the expulsion of feces from the rectum. In certain persons, and occasionally in all persons, especially in diseases where the fecal mass is in a semi-fluid or fluid form, the strongest effort of the will cannot resist the expulsive contractions of the rectal muscle. The sphincter is kept in a state of tonic contraction by a nervous centre situated in the lumbar portion of the spinal cord. The fecal mass, supported by the bladder and the rectum, does not at first touch the sphincter; the rectum is usually empty; but when the column has been well driven into the rectum peristaltic action is excited in the rectal walls and the sphincter is firmly pressed upon. The lumbar sphincter centre is now inhibited, and the ring of muscle opens, the accessory and voluntary muscles contract, and the expulsive act is completed. In the well-ordered and healthy individual the rectal walls and the sphincter do not receive the maximum of irritation from pressure of the advancing column but once in twenty-four hours. The habit of having one movement in each day is, it may be believed, in accordance with the natural and physiological demand, although both the number and the hours of evacuating are fixed to a great extent by education. The habit once established, the mechanism of expulsion recurs at the same hour and entirely without the direction of the will. If the desire be resisted, it will be most apt not to return until the same hour on the next day.
Defecation depends for its normal character upon the healthy functioning of the organism, but especially upon the normal processes of digestion. The character of the rectal contents as to composition and consistence, and the time of the arrival of the mass at the sphincter, are regulated by the taking of food at stated hours and by its normal digestion and absorption. Unaltered or partly-changed remains of the ingesta pass down the bowel, mingling with the secretion from the intestinal glands and with mucus and epithelium. As this mass passes into and through the colon, being propelled by regular peristaltic waves, it acquires odor from the development of a substance which is a final product of the putrefaction of albumen.1 Gradually the more fluid elements are absorbed, and in the descending colon a less fluid or semi-solid consistence of the feces is reached. A healthy digestion and assimilation, with active and regular contractile movements of the muscular walls of the small and large intestines, are essential to normal defecation.
1 Ewald, Lectures on Digestion, New York, 1881, p. 106.
Constipation may be defined to be that condition in which there is a prolonged retention of the feces or in which they are habitually expelled with difficulty or in insufficient quantity.2 While there are individual peculiarities due to habit or nature, the custom with most persons of having one movement in the twenty-four hours would cause any longer retention of the rectal contents to be considered constipation. The limits between health and disease are not well defined, and a failure to evacuate the bowels for several days need not be considered pathological nor require medical interference. In persons otherwise in good health such an occurrence due to neglect, change of habit or diet, as in travelling, would cause no interruption to health or comfort. Nature brings relief sooner or later and re-establishes order and regularity. In many cases constipation is a primary disease and the cause of many secondary disturbances, but it is often the effect or the symptom of various acute and chronic diseases. It may be acute or chronic.
2 Cases of constipation due to mechanical obstruction from changes in the wall of the intestine or to exterior pressure will not be considered in this article.