There are two forms, the high and low enema. The latter may be administered with any suitable irrigating tip, but for the former is required a rectal tube, more properly called a colon tube. The tube, lubricated with some bland oil and inserted into the rectum should be gradually advanced until it has been introduced about fourteen inches. This is much more easily accomplished if the solution is allowed to flow as soon as the tube is introduced and then the tube advanced while the solution is flowing. In the selection of a tube care must be taken not to get too soft a one, as the tendency of a soft tube is to double on itself.
The patient should be either in the dorsal position with the hips elevated, or lie on the right side, the thighs flexed on the abdomen. From 500 to 1,500 c. c. of solution is introduced at a temperature of about 100° F., and the character of it depends upon the action desired. The more commonly used are for catharsis: solution of salt; soapsuds made by stirring castile soap in hot water until suds are formed; a mixture of glycerine and water in the proportion of one to three; if there is tympanites, spirit of turpentine, three-fourths of an ounce to a quart of water; if there is faecal impaction, olive oil.
Frequently an injection into the rectum with a hard rubber or glass syringe of five c. c. of glycerine to five or ten c. c, of water is very efficient in causing a movemenl of the bowels, acting very much better than glycerine suppositories.
Instead of the above fountain apparatus for rectal injections, the bulb syringe is often used.
In infants a small catheter, 1G or 18 French, may be used in place of the rectal tube.