Rectal Absorption

That all mucous membranes are capable of absorbing certain materials from their surfaces and passing them into the blood vessels or lymphatics has long been recognised; but it is only of comparatively recent years that this knowledge has been applied extensively to the purpose of nourishing patients by means of the rectum, and the fact is now established that sufficient aliment may be absorbed from the mucous membrane of the rectum or sigmoid flexure alone to sustain life for a considerable period, amounting in some cases to from four to seven weeks. Moreover, the rectum may be utilised for accessory feeding for many cases in which the stomach is able to digest some food, but not in sufficient quantity to prevent emaciation.

Whenever rectal food enemata are employed certain principles should be observed:

1. The rectal surface must be cleansed from all mucus and faeces.

2. The irritation of the rectum should be allayed as far as possible.

3. The quantity and quality of food thus administered should be so regulated as to avoid exciting peristalsis, and yet allow of the complete absorption of one injection before another is given.

The minutest details which will secure the best conditions for absorption should never be regarded as too insignificant. Some patients find the idea of rectal feeding very repulsive, and dislike to submit to it; but with a little tact and perseverance their objections can usually be overcome.

Conditions Necessitating Rectal Feeding

The conditions which may require the use of rectal feeding are these:

I. Temporary obstruction to the entrance of food into the alimentary canal. Rectal feeding must be resorted to until the obstruction - such as the presence of new growths and foreign bodies, or inflammatory conditions with swelling in the mouth, pharynx, or oesophagus - can be overcome.

II. Inability to swallow food from coma, delirium, or paralysis affecting the mechanism of deglutition, as, for example, post-diphtheritic paralysis.

III. Extreme irritability, pain, acute inflammation or ulceration of the upper portion of the alimentary canal, such as that excited by corrosive poisons like carbolic acid, ammonia, etc.

IV. Stricture occurring in any part of the alimentary canal above the rectum.

V. Prolonged reflex vomiting, such as may occur in pregnancy and seasickness.

VI. Gastric ulcer, for the purpose of resting the ulcerated surface and allowing it to heal.

VII. Cancer of the stomach with inability to absorb or digest sufficient food, especially with obstruction to either the cardiac or pyloric end of the organ.

VIII. Any form of severe gastric irritation, such as occurs in acute gastritis.

IX. Exhausted conditions of the system which may be present during the course of severe fevers in which absorption of even pre-digested food is largely suspended.

X. For the insane who refuse food by the mouth.

XL To supplement the action of a feeble stomach, or when for any reason, such as total lack of appetite, emaciation is rapidly progressive.