With regard to the symptomatology of amœbic dysentery, Castellani and Chalmers distinguish four types—the acute, chronic, latent, and mixed types.
The acute type has an abrupt onset; pain is felt in the lower part of the abdomen, and the motions, rarely exceeding thirty daily, are accompanied by much griping and straining. Blood and mucus are present in the motions, and occasionally greyish material, consisting of leucocytes, mucus, Charcot-Leyden crystals, amœbæ, and bacteria, sometimes with particles of tissue. Nausea and vomiting may occur. Digestion is usually deranged. The abdomen is sunken, the liver and spleen are normal, but tenderness is felt along the course of the large intestine. The urine may be diminished in quantity.
The chronic type may succeed the acute, or appear like diarrhœa, the motions being fæculent and containing mucus. Between exacerbations, constipation may occur. The number of motions may only be twelve to fourteen per diem. Gangrenous complications may occur at any time, and chronic dysentery may persist for many years.
The latent type is important, as the patients, though free from dysenteric symptoms, harbour amœbæ and act as parasite carriers. The latent condition may lead to acute attacks or to liver abscess.
The mixed type occurs where amœbic and bacillary dysentery are combined. There is much fever, nausea, and vomiting. The motions are numerous and often very offensive.
Treatment.—The most modern method of treatment, due to Leonard Rogers, is by emetine. According to Castellani and Chalmers, it is well to relieve griping and straining by either a hypodermic injection of morphia or by small enemata of 40 minims of laudanum in 1 oz. of mucilage of starch or by using 1/4 gr. morphia or 1/4 gr. codeine suppository. A dose of castor oil (ʒiv to ʒvi) with or without a few minims of liquor opii sedativus or a few doses of saline may be given during the first twenty-four hours. After the castor oil has acted or simultaneously, emetine treatment should be commenced; 1/3 to 1/2 gr. of emetine hydrochloride, dissolved in sterile normal salt solution, is injected hypodermically three times a day for two or three days.
If emetine cannot be obtained, 5 gr. doses of ipecacuanha every three to six hours in the form of membroids, or as pills coated with salol or keratin, can be substituted.
After acute symptoms have disappeared, intestinal irrigations once or twice daily, on alternate days, are useful. A solution of tannic acid (3 to 5 per 1,000) or of quinine bihydrochloride varying in strength from 1 in 5,000 to 1 in 750 is very slowly injected in quantities of 1/2 to 3 pints by means of a long, soft, rectal tube.
For gangrenous dysentery Castellani and Chalmers state that appendicostomy, with irrigation of the whole lower bowel with quinine lotion (1 in 1,000) or collargol (1 in 500), is the only chance.
The use of emetine should be continued in smaller doses after the dysenteric symptoms have ceased, in order to prevent relapses and as a possible safeguard against the development of a liver abscess.