Ether is sometimes given by rectum, the bowel being thoroughly cleansed beforehand. It may be given with oxygen or oil as the diluent. The opportunity for free exit of the vapor is considered a necessity. Gwathmey's oil-ether colonic method is to give by rectum one hour before the operation a mixture of morphine alkaloid, gr. 1/8 (0.008 gm.), paraldehyd, 1 dram (4 c.c.) and ether and olive oil, each 3 1/2 drams (14 c.c.), and then to use a mixture of if ounces (45 c.c.) of olive oil and 4 1/2 ounces (135 c.c.) of ether as the main anesthetic about twenty minutes before the operation. The ether vaporizes by the body heat, leaves the oil, is absorbed, and is perceptible in the breath in three or four minutes. If a lightening of the anesthesia is required he extracts some of the oil, and uses a Connell breathing tube.

Rectal anesthesia is a means of avoiding the distress of the first stage and the irritation of the respiratory tract; it is said to lessen the post-ether nausea and vomiting. It is sometimes followed by hemorrhage from the bowel or by diarrhea or colitis from irritation of the bowel, so must be used with great care. The author has learned of a case of colonic anesthesia in which death followed enormous distention and rupture of the colon.

This was presumably due to the combination of three factors, viz., the expansion of the ether vapor by the warmth of the body, the non-resistance of the bowel owing to its loss of muscular tone, and the lack of a free exit for the gas. Cunningham reports a death in a case of amebic colitis.

The special value of rectal anesthesia is in operations about the head and neck, or in patients with inflammatory conditions of the respiratory tract.