DIARRHEA in early life is a subject of the utmost importance, as to it a large proportion of the deaths which occur in infancy are to be ascribed. The term itself is a vague one. It expresses merely an injurious increase in the alvine dejections, without reference to cause, and is applied equally to a trifling derangement, and to a serious, or even fatal illness. It there fore embraces several varieties of intestinal disorder which are clinically distinct, although, anatomically, perhaps, they may present mere differences in degree of the same pathological condition. For practical purposes it will be convenient to describe three forms of bowel complaint. Simple non-inflammatory diarrhcea, (mild intestinal catarrh) ; acute inflammatory diarrhoea (severe intestinal catarrh, or entero-colitis), and choleraic diarrhoea (infantile cholera). Of these, the first only will be treated of in the present chapter.
In simple non-inflammatory diarrhoea, the mucous membrane of the bow els is in a state of temporary irritation, resulting from a mild form of catarrh. The disorder is a mere derangement of function, is, as a rule, accompanied by no great violence of purging, and is quickly arrested by suitable treat ment. By many writers, this form of diarrhoea is not separated -from the more severe variety of muco-enteritis, which will be described afterwards. Its clinical characters are, however, so different, and its symptoms so much less serious, that it is convenient to devote a special chapter to its con sideration.
Causation.—Improper feeding is one of the most frequent causes of looseness of the bowels. Amongst band-fed babies, the disorder is especi ally common, and unless quickly arrested, is very apt to run on into the in flammatory form, and prove serious. The food may be excessive in quantity, or unsuitable in quality. Often it is both, and an infant of a few months old is supplied with an amount of farinaceous food far in excess of his powers of digestion. The food is consequently carried along the alimen tary canal, fermenting and irritating the mucous surface over which it passes, until it is discharged. A common cause of looseness of the bowels, is the practice, which often prevails in badly-regulated nurseries, of pre paring for the infant in the morning the whole day's supply of food. The
mixture of milk and sweetened farinaceous matter seldom remains un changed for many hours together, and often, after a short time, is quite unfit for the child's consumption. But besides infants, children of all ages are subject to temporary looseness of the bowels, from the irritation of un digested and fermenting food. In such cases, the alvine flow may be re garded as the natural effort of the bowel to relieve itself of an unwelcome burden. The danger is, that in infants, and weakly children, the mild catarrhal process may not cease with the expulsion of the offending sub stance, but may pass on into the more serious form.
A cause which is little less common than the above, is chilling of the sur face. Children, and especially young babies, are very sensitive to changes of temperature, and part with their heat very rapidly. Unfortunately, it is at this susceptible age that the body is habitually less cci.vered than at any other period of life. From the time that the child relinquishes his first long clothes, until his third or fourth year, he is exposed, with insufficient protection, to frequent changes of temperature. At all seasons, while in doors, his legs and arms are bare—often his neck and shoulders as well ; and not seldom from the waist downwards he is covered by nothing but his short and scanty skirts. It is not, then, surprising that in a changeable cli mate the child should be subject to frequent chills, and that diarrhoea should be so common a complaint. In England, the derangement is especially prevalent at the end of spring and the beginning of autumn—seasons when the warmth of the day is rapidly succeeded by the cool of the evening. Moreover, it must be within the experience of most medical practitioners, that the sudden alternations which sometimes occur, even in the height of summer, from excessive heat to a cool, or even chilly temperature, are generally followed by an outbreak of diarrhoea amongst the younger members of the community. Rickety children, probably on account of their profuse and ready perspirations, are especially liable to these attacks.