These insidious cases are more common during the second year of life, than at any other period, although they may also occur later. When the complaint arises as a result of an acute attack, chronic diarrhcea, is often met with during the first year, and is especially frequent in infants who have been weaned early and fed afterwards on unsuitable food.
Diagnosis.—Inflammatory diarrhcea, if accompanied by may be confounded with typhoid fever. The distinguishing points between these two diseases are pointed out elsewhere (see page 83).
The severity and danger of the attack may be detected from the first., by noticing that the temperature in the rectum is raised. In simple diarrhcea, the temperature is normal after the first stool. It is a question of con siderable interest to ascertain the exact seat of the catarrh. The presence of jaundice would, of course, indicate that the duodenum was involved ; and tenesmus, with or without prolapsus ani, would point to the rectum. From a series of careful and laborious investigations, carried out by Prof. Noth nagel, who submitted to microscopical examination more than one thousand specimens of catarrhal stools, considerable addition has been made to our knowledge of the distribution of the lesion iir cases of intestinal catarrh. According to this authority, mucus is passed in considerable quantity in other forms of catarrh besides that affecting the lower bowel, and can be detected by the microscope when not visible to the naked eye. The amount of mucus, and its more or less intimate admixture with the fcal matter, fur nishes important evidence ; so, also, from the presence or absence of bile stained mucus and epithelium, much information can be derived. The re sults of Prof. Nothnagel's researches may be thus briefly summarised : If the catarrh affect the jejunum and ilium, no mucus can be seen by "ordinary inspection of the stools ; but when a specimen is placed under the microscope between two thin plates of glass, islets of mucus are distinctly visible. We can then affirm positively that the catarrh is seated in the small intestine, and that the colon is healthy. If the mucus is tinted with bile pigment, it also indicates jejunal and ilial catarrh ; but, in addition, it shows that there is increased peristaltic action of the colon and the lower part of the ilium. In these cases, the stools are always liquid, for if re tained in the colon sufficiently to acquire firmness, the bile pigment is always transformed, and the play of colours in Gmelin's test can no longer be obtained. Besides bile-stained mucus, cells of cylindrical
epithelium, leucocyte-like corpuscles, and fat-globules, all tinted with bile, can be observed. In addition, on examining the urine, the indican' ex cretion is found to be in excess.
When the larger bowel is affected, no bile-tinted mucus globules can be perceived. The stools are of a pulpy consistence, and the mucus they contain is distinctly visible to the unassisted sight. The nearer the af fected part of the bowel is to the cacum, the more intimate is the admix ture of the mucus with the general fmcal mass. If pure mucus is passed in large quantity, we may conclude that the siamoid flexure or the bowel below it is the part involved ; and scybala embedded in mucus, point dis tinctly to the rectum.
Spurious hydrocephalus does not present much difficulty in diagnosis. The history of disease, the depressed fontanelle, the low tem perature, and the signs of general prostration, sufficiently mark out this condition from the ordinary forms of cerebral disease.
Prognosis.—Inflammatory diarrhoea is so fatal a complaint in weakly children that it is very important to estimate the chances of a favourable ending to the derangement. Much will depend upon the age of the child, the sanitary conditions under which he is living, and the state of his pre vious health. The disease is most dangerous in babies who have been weaned early, and fed afterwards on excess of farinaceous food, or with por tions of their parents' meals. Such infants are weakly and ill-nourished at the time of the attack,, with irritable bowels from their unsuitable diet. A severe acute catarrh coming on under such conditions, rapidly reduces their remaining strength, and very commonly ends fatally. Older children, having greater vigour, are often able to battle through a complaint which would kill a younger and weaker subject. Therefore, after the age of in fancy has passed, the prognosis is more favourable than at an earlier pe riod ; but even in these cases, if the attack is violent and the purging severe, the danger is not slight, and the derangement may resist all our efforts to arrest its course.