Diarrhoea is one of the commonest signs of intestinal disturbance in infancy and childhood. A large number of cases will be found to be associated with improper feeding. Diarrhoea may be one of the chief symptoms of chronic intestinal indigestion, which has already been considered. In infants overfeeding, too frequent feeding, and improper food will often cause diarrhoea, with or without the addition of gastric symptoms, vomiting, etc.

The preventive treatment consists in the use of proper food for infants and children. Of special importance is the freshness of the food, milk, fruit, etc., for the most severe cases are those in which some decomposition has taken place in the food. This is the cause of the most fatal form of diarrhoea in early life, namely, the acute summer diarrhoea of infants. It is inadvisable in the case of breast-fed babies to wean during the hot season, as diarrhoea is very easily induced by a change of diet at this time. Whatever views one may hold as to the relative advantages of boiled and unboiled cows' milk, it may be safely asserted that in hot weather all cows' milk for children's use should be boiled for two or three minutes and then kept on ice in a closed or covered vessel. The greatest cleanliness should be observed in connexion with the feeding-bottles, and no "dummy" soothers should be allowed in the infant's mouth. The tendency to give young infants some fruit, which is so common amongst nurses during the hot season, should be severely discouraged as being distinctly dangerous. In older children the indiscriminate use of sweets and sweet cakes is responsible for many cases of diarrhoea. While fruit is good for them, care must be taken to see that it is ripe, as both unripe and too ripe fruit is a fertile source of diarrhoea.

The treatment of slight attacks of diarrhoea in breast-fed babies consists in diminishing the frequency of the feeding times, or the amount given at each meal. Sometimes, although rarely, the maternal milk does not suit the child, and chronic diarrhoea results. If one cannot correct the breast milk by treating the mother, it may be necessary to put the child on some other food. In the case of bottle-fed babies diarrhoea is often due to an excessive amount of starchy material in the diet. One must therefore remove this source of trouble, which usually takes the form of some patent food, and put the child on to a proper dietary. A few days of low feeding and plenty of water to drink will cure these mild or chronic cases of diarrhoea in infants. The same applies to the case of older children where the dietetic element will be found at fault.

The most severe form of diarrhoea in early life is the acute Summer diarrhoea of infants. It is essentially a disease of bottle-fed babies, or of those who are receiving some food in addition to the breast milk. The origin of the disease is traceable to certain organisms in the food, chiefly in cows' milk, which multiply and cause intense irritation in the stomach and intestines. The exact method by which the milk is contaminated is unknown, but there is much evidence in support of the view that flies are the chief means by which the milk is infected. In many houses milk, whether fresh or tinned, is open to this source of contamination owing to its being left in an exposed condition, and wherever milk is there flies will gather.

During the summer printed papers containing the following instructions are given to all the mothers attending the Paddington Green Children's Hospital.

"In hot weather milk quickly turns sour or becomes tainted by dust, dirt, and flies, and may easily bring on diarrhoea unless the following precautions are taken: -

"Buy the milk twice a day - not once only - and get the best cows' milk you can, as cheap milk is always dangerous.

"Boil it at once for one or two minutes.

"Then place it in a covered vessel in a basin of cold water and keep cool. The milk must be covered over to prevent dust and flies from reaching it.

"Always taste the milk, in a spoon, before putting it in the bottle, to see that it has not turned sour. Do not put the teat in your own mouth at all.

"Do not keep any milk left in the bottle for the infant's next meal. Use it for yourself or the rest of the family.

"The bottle should be boat-shaped with an india-rubber teat, but no long rubber tube.

"The bottle should be scalded out after use, and cleaned with a bottle brush, which should be boiled immediately before using.

"After each feed the nipple should be turned inside out and washed, and kept with the bottle in cold water.

"Good milk is often spoiled by dirty bottles.

"When fresh cows' milk cannot be obtained, or the milk has turned sour, use the best sweetened condensed milk.

"Get small tins, as after the tin is opened the milk will soon go bad.

"Cover an opened tin with clean muslin or butter cloth to protect it from dust and flies, and keep in a cool place.

"In any case of sudden diarrhoea or vomiting stop the milk at once, and give only plain water which has been boiled, or barley-water.

"In hot weather do not keep bones, stale vegetables or fruit, and other rubbish for the dustbin in the room or house. Rubbish breeds flies, and flies poison the food they settle on".

In acute summer diarrhoea milk in any form must be stopped at once. It is especially dangerous in this disease, because it usually conveys the poison which is the starting-point of an attack, and is a good medium for the further growth of the organisms in the alimentary tract. We have therefore to find some temporary substitute during the time that attention is being devoted to thoroughly clearing out the gastrointestinal tract. In very acute cases the best plan is to stop all food entirely and to give only boiled water or barley-water or rice-water for twenty-four or forty-eight hours. This usually meets with a strong protest in the domestic circle on the ground that the infant will be starved to death. The anxious mother may be assured that the infant is incapable of digesting or absorbing any food, and her attention may be directed to the motions, where the milk given has appeared quite undigested. As the thirst is usually very great, water should be administered frequently, every hour or two hours, but in small quantities as vomiting is so easily induced. If the vomiting is very severe it may be necessary to give only one or two teaspoonfuls of water at intervals of fifteen or twenty minutes. The great loss of fluid produced by the diarrhoea often leads to a condition of collapse, of shrivelling up of the tissues, and of cardiac weakness. Fluids cannot well be administered per rectum to infants, but the subcutaneous injection of normal saline fluid (1 drachm of common salt in a pint of boiled water) will prove beneficial. A Southey's or other small trocar may be used, and the hot sterile fluid should be allowed to flow by gravitation into the loose tissues of the axilla or abdominal wall. From 6-8 oz. may be injected at a time, and the fluid should be allowed to enter slowly, so as to avoid the risks of sloughing or haemorrhage. The tissues will absorb the fluid rapidly, and the restorative effect on the patient is often marvellous.

A little brandy is probably beneficial as a stimulant if given well diluted - a teaspoonful in half a pint of water during the day, and the same amount during the night.

At the end of thirty-six or forty-eight hours, or when sufficient time has been allowed for the thorough emptying of the bowels by medicine, a beginning should be made with food in the shape of albumin water, or weak veal, mutton or chicken soup. Here the rule must be to proceed very slowly and gradually, watching the effect. Albumin water may be made at first of the strength of half an ounce of the white of egg to half a pint of water or barley-water, and this may be rendered more palatable by the addition of 2 drachms of extract of malt. Similarly an ounce of soup may be diluted with 5 oz. of water. As regards the feeding the rule should be to feed every two hours by day and not oftener than every four hours by night, and only to give small quantities at first - say 1 or 2 oz. If the thirst is great, no harm is done by giving the infant water freely between the feeds. This modified diet may be carried on for one or two days, until the diarrhoea is somewhat lessened, and the motions are not of a purely mucous character. If the albumin water is found suitable there is no occasion to give the soup, but in some cases the soup seems better tolerated.

The third stage is reached when we commence tentatively a return to milk food. A trial of milk in one or other form should be made by alternating it with the albumin water. Of the various forms in which milk may be used at this time the following represents a scale of digestibility : (1) peptogenized milk (without added cream), (2) whey, (3) condensed milk (diluted with twenty-four parts water), (4) equal parts of cows' milk, lime-water, and barley-water. Citrated milk (gr. 1 of citrate of soda to each ounce of milk) may also be found suitable. It is not necessary to take every infant through these four stages, but in one patient one form of milk will be found to agree best, and in another patient some other form. If the milk provokes a recurrence of vomiting or diarrhoea, it must be at once stopped. Toleration will not be readily established and in no case must an attempt be made to feed up the patient rapidly. The chief points about the dietetic treatment are : (1) to give no food until the stomach can retain and digest it, (2) to begin with very weak foods, and very small meals, and (3) to let the patient have as much water as he can retain, so as to help in washing out the bowels.