This is an affection of early infancy to which attention has only recently been directed. Cases are still being frequently overlooked, the proper treatment is not carried out, and the infants die. As the disease is not fully described in many textbooks, we shall refer first of all to the clinical symptoms, which are as a rule clearly defined, and allow of an early diagnosis being made if the possibility of pyloric stenosis be kept in mind.

The history is usually as follows : An infant, healthy at birth, seems to progress satisfactorily for two, three, or five weeks, and then vomiting comes on. It does not matter what the food is, breast or artificial feeding, the vomiting persists. Frequently it is suggested in such a case to try another food, and the baby is started on a career of different diets. A most misleading occurrence in this connexion is that a change of diet has often a temporary effect in checking the vomiting. It may be only for a day or a week, but the cessation of vomiting suggests that the disturbance is due to the food, that the appropriate food has not been found, and so the hunt continues. The result is usually the same - failure of the treatment and death of the child. The vomiting is really a regurgitation of the food, without any of the signs of nausea, gastric catarrh, or acute disease. At the beginning it is moderate in amount, not specially violent, and only occasional. As time goes on - and time is measured by days in this affection - the amount of vomited material becomes larger, representing two or three feeds, and the violence of the vomiting is much greater, the food being shot out through the mouth and nose for some distance. The vomited matter consists only of the food, partly digested. Occasionally blood is present, but never bile. The amount vomited may be considerably greater than a normal stomach could contain at this age, showing that dilatation has taken place. The frequency of the vomiting varies, sometimes occurring only once a day, and at other times more frequently. The act of vomiting does not distress the patient, in fact it often brings relief, and the child is at once ready for another feed. It is almost characteristic of these cases that the infants are always ready for a feed, being in a chronic state of hunger. The infant wastes rather rapidly at first, and then more slowly, but steadily. A careful physical examination will usually reveal either marked peristaltic contraction of the stomach, or an enlarged and hardened pylorus, or both.

All are agreed as to the clinical symptoms, but a good deal of difference of opinion exists as to the pathology. A hypertrophic condition of the muscular tissues of the pylorus is always found at operations or on post-mortem examination in typical cases, although occasionally in practice one meets with atypical cases in which probably spasm is present without hypertrophy. The latter are much more amenable to medical treatment. The hypertrophy is believed by some to be due to a congenital hyperplasia of the pyloric muscle (Cautley), and by others to be the result of persistent spasm. From the therapeutic point of view it is important to note that the pyloric spasm is the chief factor, as owing to the spasm the food is unable to pass the pylorus. A condition of hyperplasia or hypertrophy should not, and probably does not, of itself prevent the pylorus from relaxing, but it may tend to render spasm more easily induced, and more persistent than under normal conditions. There is clinical evidence in favour of the view that such spasm is caused by the irritation of food in the stomach. However carefully an infant may be fed, some gastric disturbance or indigestion must happen at times, and this may be the starting point of a pyloric spasm which tends to persist. Hence we find that although the lesion is probably congenital, the symptoms may not appear for two, three, or even six weeks. The sequence of events would appear to be, first gastric irritation, secondly pyloric spasm, and thirdly hypertrophy and dilatation of the stomach from its efforts to drive the food through the pylorus. The vomiting is induced by the irritation of the stagnant gastric contents, and sometimes by the large quantity of food which accumulates in the stomach.

The important medical measures are, first, suitable feeding, and secondly, washing out the stomach (lavage). The food requires to be such that it can be completely digested in the stomach, so as to leave no solid residue to induce pyloric spasm.

The difficulty therefore lies in the casein and the fat of milk. No food is better than breast milk, provided it is of normal quality and contains no excess of fat. This should be determined by chemical examination, and if necessary the mother's diet can be altered so as to bring her milk to the proper standard. In any case the breast milk should not be discarded until a strong effort has been made to use it successfully. Fresh cows' milk as commonly used in infancy is not as a rule well tolerated in this affection, at least for some time, and one has usually to commence with some substitute in which the casein is more digestible and the amount of fat is kept small. Peptogenized milk or whey may be used. In such cases also life can be maintained by the use of certain foods which are of themselves incomplete, but which are capable of being digested in the stomach, such as Allenbury's food (No. I), Mellin's food, or malted milk. Whatever the diet is, the food must be given well diluted at first, and gradually increased in strength as toleration is established. A method which will be found useful is to alternate weak whey or peptogenized milk with one of the foods mentioned above. Sugar in the form of malt extract may be given in excess of the normal requirements, as it is very digestible. A little orange or grape juice may be given in water. A few drops of raw meat juice may be added to each feed or alternate feed.

To ensure complete digestion in the stomach the quantity given at a time must be small, and the frequency of the meals must be increased. From 2-3 oz. is usually as much as should be given at a time, and less may be called for if vomiting persists. The feeding will often require to be carried out every two hours during the day and night, and sometimes one will obtain better results by feeding every hour during the day. Both the quantity and the frequency of the feeds must be regulated according to the results of experience in individual cases. One must not expect that the fattening up process will go on rapidly. Every attempt to increase the fatty element in the diet is often followed by gastric disturbance and increased pyloric spasm. The administration of cod-liver oil by inunction, if it be of any value, would appear to be specially suited to the conditions present, owing to the difficulty of getting fat into the system by the natural channel. Rectal feeding in the case of young infants cannot be carried out with any success. In many cases the tissues are dried up from the loss of fluid, and the use of saline injections, both subcutaneously and per rectum, is beneficial. From 4-10 oz. of normal saline solution may be injected subcutaneously every day, and will act as a restorative until the improvement of the pyloric function allows of the entrance of a sufficient amount of fluid by the natural route. In cases in which the infant is much reduced or has a subnormal temperature, brandy, up to a drachm daily, will be found of service as a general tonic.

Gastric lavage is useful in two ways, first in removing all irritating remnants of food from the stomach, and secondly in showing the physician how to regulate successfully the food and feeding. For the latter reason it must be carried out under the supervision of the physician, and not left to a nurse. The stomach should be washed out once a day for a prolonged period, and in bad cases this proceeding may be required twice daily for a time. It should be done when under normal conditions the stomach is empty, i.e. two or two and a half hours after a meal as the case may be. The wash-out should show a small amount of soft, flocculent matter, which tends to get less in successful cases as time goes on. If, on the other hand, a large amount of matter is washed out, or undigested curds, it is clear that the food is not being properly digested, and will maintain the pyloric spasm. The food materials must be changed, or at any rate that food which is not properly digested, and it may be that the quantity of food and frequency of feeding will have to be altered. Dr. Cautley has pointed out that in many cases the mere washing out of the stomach systematically will check the vomiting, and that this may prove misleading. This is true, and enforces the importance of examining carefully the nature of the stomach contents in order to judge whether they are likely to pass the pylorus. If the residue is of the soft flocculent nature described above, one may reasonably expect that it can and will prove non-irritating, and will eventually pass through the pylorus.

The signs of successful feeding in these cases are as follows The vomiting ceases. The bowels come to act naturally. This is in marked contrast to what happens in untreated cases, where marked constipation is the rule, artificial aids per rectum being very often required, and the motions contain little faecal matter. The stomach peristalsis becomes less marked, and gradually passes off. This is due to the absence of irritating food material which the stomach had previously been trying to drive through the pylorus. The discomfort, pain, apathy, and constant whining of the infant cease. This is owing to the appetite being satisfied by the entrance of food into the system. The nutrition of the infant is improved, as shown by the healthier colour, the increased activity of the limbs, and a slow gain in weight. It is very important to remember that these infants cannot be fattened rapidly, that any attempt to secure this will probably end in disaster, and that the less weighing there is the better, especially if there are anxious relatives about. The most suitable foods are not fattening ones, and any excess of food is apt to produce disturbance in the stomach and bowel. On the other hand, the vital powers of the infant can be very much improved, and the disordered functions restored to healthy action, by a simple diet, and the fattening materials can be reserved to a later period. The increase in weight of the infant is somewhat fluctuating at first, and tends to become steady as time goes on, but is always slow.

A common complication in the course of treatment is diarrhoea. In cases of pyloric stenosis the bowel has been out of use for some time, and is consequently unprepared for the food material which now passes through the pylorus. Hence arises what is probably a form of irritative diarrhoea, which is always serious and may prove fatal. In such cases it is advisable to reduce the amount of food by one-half, and to give sips of hot water frequently. After an attack of vomiting no food should be given for at least two hours, so as to rest the stomach. Intestinal flatulence is to be treated, like diarrhoea, by a temporary reduction in the amount of food.

We have entered rather fully into this somewhat rare condition of pyloric stenosis, but believe that the importance of the dietetic treatment fully justifies it. Until recently operation was regarded as the only possible method of cure; but within the last two years many cases have been cured by means of dieting and lavage. At the same time it may be stated that no disease will tax the practitioner's powers and resources in the matter of dieting more than congenital pyloric stenosis.