Blood

Dried beef blood has sometimes been used as a rectal food, but there is no evidence that it is absorbed. In those cases in which I have employed it it has usually caked within the rectum and prevented the absorption of other materials. Fresh defibrinated blood has also been used for the same purpose - four ounces may be given every six hours - but it possesses no advantage over pre-digested milk or peptones, and is not to be recommended.

Milk

Pancreatinised milk in which the process of predigestion has not been carried too far is, on the whole, one of the most satisfactory foods which can be used by rectum. It should not be rich in cream.

Eggs

Huber proved by experiments upon patients in nitrogenous equilibrium that the rectum absorbs 25 to 35 per cent of the nitrogen of raw eggs, 70 per cent from raw eggs with sodium chlorid, and 75 per cent from peptonised eggs. The whites of two eggs may be added to peptonised milk, or, better, to peptone solution or one of the meat extracts. Ewald, who has experimented extensively with rectal alimentation, states that unpeptonised egg albumen is absorbed as promptly from the rectal surface as commercial peptone, while peptonised egg albumen is taken up even better. The absorption of albumen is furthered by the addition of a little table salt to the injection - about fifteen grains to each egg.

The yolk of egg is not recommended for rectal use, for although it contains albuminous material, so much fat is mixed with it, which is not absorbed excepting by the intestinal villi, that it is useless.

Grape Sugar

Ewald has demonstrated the existence of anastomoses between the superior and middle haemorrhoidal veins, extending to within three inches of the anus, hence making it possible for any carbohydrates absorbed per rectum to reach the portal system direct and be assimilated by the liver. Of the various carbohydrates, it has been proved by Schonborn that a solution of glucose is best absorbed. The solution should not be stronger than 10 cc. in 100 cc. of water, and should not-be used too often, or it may prove irritant and excite diarrhoea. As much as 95 per cent of such solution may be absorbed.

The addition of salt to all forms of food enemata aids in their absorption.

Alcohol

The alcohol used for rectal injection should be in the form of good liquor, somewhat diluted. If pure alcohol is given, it should be diluted in three or four parts of water, when it becomes less irritating to the mucous membrane and is more easily absorbed. Very often a small injection of half an ounce of whisky in an ounce and a half of water, or even an injection of whisky, brandy, or sherry and water given alone, will be retained and completely absorbed, when a larger volume of fluid or other ingredients added to the alcohol will not be retained, and the whole enema will pass out again. Rum may be used, or brandy, but, as a rule, good whisky is the most serviceable. When alcohol is given in connection with other rectal foods, it may be unnecessary to dilute it with water, but undiluted whisky sometimes causes precipitation in milk. If added too strong it coagulates casein which has not been pancrea-tinised, and no solid matter, even in the form of a fine precipitate, is of much use in the rectum, where it acts as an irritant.

Prescriptions For Food Enemata

Ewald recommends the following: Beat the whites of two eggs with a tablespoonful of cold water, add a teaspoonful or two of starch boiled in a half teacupful of a 20-per-cent glucose solution, a wineglassful of claret and a teaspoonful of peptone solution. Mix at a temperature below the coagulation point of the albumen.

Yeo prescribes expressed meat juice, egg albumen, and peptones.

Leube prefers the mixture of scraped meat and fresh pancreas made into an emulsion as prescribed above (p. 414).

Roberts gives milk gruel and beef tea, with two teaspoonfuls of liquor pancreaticus freshly mixed. He reports a case in which he sustained the patient's life for nine weeks upon this treatment alone.

Food Suppositories

Rectal food suppositories are sometimes made of predigested and evaporated or condensed forms of milk or meat juice, which are mixed with oil or cacao butter and pressed into an elongated bougie or suppository. They sometimes prove useful, and are certainly convenient, but they possess no real advantage over nutrient enemata, and if rectal feeding is to be long continued, the latter are found more practical.