injected into the rectum, suspended in saline solution, were carried by reversed peristalsis into the small intestine, and in some instances even as far as the stomach. In 1902, Cannon (2) introduced into the rectum of certain animals large or small amounts of food mixtures of different consistency, containing bismuth subnitrate, and then studied the results by the use of the X-ray. Cannon's experiments prove that in every instance antiperistaltic waves were set in motion by the injections and the material was thereby carried to the cæcum. Small injections of nutrient material never passed this point. The larger injections, however, did not stop when they reached the ileocæcal valve, but were carried high up into the small intestine. After such nutrient injections were given, Cannon frequently observed the normal rhythmic segmentation of the intestine, which produced the same effect upon the food as if it had passed through the stomach in a normal manner. Experiments on dogs, carried on in 1869 by Bauer (3) under the direction of Professor Voit, proved that all proteins were largely absorbed, as shown by an increase in the urinary nitrogen. He ascertained the daily excretion of urea in starving animals and then gave rectal injections of albuminous substances, peptone solutions, fat and raw starch. Following these injections there was a marked daily increased elimination of urea, which was taken as evidence that the albuminous substances were absorbed by the large intestine. An examination of the fæces the next day failed to reveal any starch or sugar, and he therefore concluded that starch was digested in the large intestine. In his experiments the fats were only slightly absorbed. Bauer also mentions that when sodium chloride is added to protein solutions there is an increased absorption. Rast (4) claims that 30 per cent. to 95 per cent. of protein is absorbed when injected into the rectum. If large quantities are used the intestine is irritated, causing a decreased absorption. This author believes that the great value of milk when injected is due to the lactose present which is readily absorbed. T* According to the observations of Huber (5) and Leube, milk proteins are not readily absorbed unless peptonized, and eggs alone are very slowly absorbed. If, however, sodium chloride is added there is an increased absorption. Dr. O. F. F. Grünbaum (6) used ox serum in rectal feeding, and selected this particular substance because it contains a constant amount of protein, which he says is easily absorbed by the mucous membrane of the large intestine. It does not require any tedious preparation and does not give rise to offensive stools. He injected 90 c.c., equal to 38 gms. of protein, every four hours. By adding 60 c.c. of milk to each enema, the protein diet was raised to 51 gms. He believes that carbohydrates in the form of starch or glucose are readily absorbed when given in solution by the rectum, and if the strength of the solution is less than 15 per cent., it is well retained and does not cause irritation; therefore 40 gms. may be introduced during twenty-four hours. From Grünbaum's personal observation 30 gms. were absorbed without the production of glycosuria. Fat, he says, is not easily absorbed by the mucous membrane of the rectum. The studies by Edsall and Miller (7), in 1900, demonstrated that fats and proteins are poorly absorbed by the rectal mucous membrane, and the amounts taken by this method are extremely small when compared with feeding by the mouth. In a paper published six years later, Edsall (8) says that proteins, fats and carbohydrates are absorbed to some extent, but not enough to prevent starvation. Pasteur (9), London, treats all cases of gastric ulcer by giving enemas of warm water without any food stuffs at all. From 6 to 10 ounces of water are given every four to six hours and this is kept up for periods varying from one to three weeks. He claims his results have been better and the patients easier to manage than formerly when milk, eggs, etc., were given. Both Leube (10) and Fleiner (II) claim that nutrition cannot be preserved by feeding per rectum alone and that feeding by the mouth must begin as soon as possible. It is maintained by a few investigators that 10 gms. of fat and 20 gms. of protein are the maximum amounts that can be absorbed in twenty-four hours. In order to preserve nutritive equilibrium, the body at rest requires 1,800 calories per day. Therefore, with the above figures there would be a marked deficiency of calories. The results of many more investigators could be quoted, but they would only tend to show the wide differences of opinion that exist as to the absorptive powers of the rectum. During the course of my practice it has been necessary many times to resort to rectal feeding in cases where the stomach was unable to perform its natural functions. Patients have been kept on rectal enemas for periods ranging from one to four weeks. While I have observed this in a clinical way only, I have always been skeptical as to the absorptive powers of the rectum for anything except water, and in those cases where patients have depended entirely on rectal feeding I have inclined to the belief that the nutrition furnished to the body was derived largely from the tissues themselves and not to any appreciable extent from the nutritive enemas. In other words, that life is sustained in such cases by drawing upon the individual's own supply of fat instead of being dependent upon the rectal feeding. Although I have given rectal enemas as a routine measure, I have been extremely doubtful as to their nutritive value, and having discussed the matter with Professor Lafayette B. Mendel of Yale University, I made, at his suggestion, a series of experiments in order to ascertain by first-hand evidence whether the mucous membrane of the rectum is capable of absorbing nutrients, and if so, whether the result of such absorption is sufficiently pronounced to sustain life for an appreciable length of time. In the course of these experiments I was assisted to a large extent by Professor Mendel and desire at this time to acknowledge my appreciation. To determine to what extent rectal absorption is effective, I have given injections of potassium iodide, sodium chloride and solutions of dextrose. These materials were selected because they were easily recognized in the urine and fæces. After rectal injections of potassium iodide, dissolved in 100 c.c. of water, I was able to detect the iodide in the urine and saliva in all instances after intervals varying from eight to twenty-five minutes after the injections were given. The experiments with sodium chloride were of a more elaborate nature and covered a period of weeks. Varying amounts were taken into the system, and in this case both through the mouth and rectum, for the purpose of showing comparative results of absorption by these two methods.1 To my surprise I found that in the case of the salt injections the absorption from the rectum was quantitatively almost as complete as in the case of oral administration, for in both instances there was a marked increase of the salt output of the urine, and only a slight trace found in the fæces when as much as 10 gms. had been taken by rectum. The following diagram will show more clearly the results obtained. An examination of the fæces of healthy individuals failed to reveal any sodium chloride, but the fæces of patients suffering with digestive disorders, such as mucous colitis, intestinal fermentation, bulimia, tubercular diarrhoea, pancreatitis and hyperchlorhydria, showed quite an appreciable amount of sodium chloride. After the taking of laxative drugs, such as phenolphthalein, aloin, and calomel, sodium chloride was also found in the fæces. On two occasions 30 gms. of dextrose were given by rectum in twenty-four hours and the fæces examined. With Benedict's solution a trace of sugar was discovered. Whether the dextrose was completely absorbed or in part disappeared through fermentation, is not demonstrated by the method employed, as the gasses resulting were exceedingly distressing. Therefore, the drop method, as first described by Dr. J. B. Murphy (12) of Chicago, was subsequently used, and absorption occurred without any unpleasant symptoms. With respect to the class of materials most readily absorbed, I found that the authorities are unanimous in the opinion that fat absorption is practically nil, so that no useful purpose 'The Volhard method, as modified by Samuel C. Harvey, Ph.B., was used for the determination of the chlorids in the urine. |