Dysentery.
This disease, which is due to an inflammatory condition limited as a rule to the lower or large bowel, may be the result of a variety of causes, but there are two chief types which must be clearly distinguished: (1) Amœbic dysentery, due to a protozoon or animal organism, (2) Bacillary dysentery, caused by certain micro-organisms belonging to the vegetable world.
Amœbic dysentery is much more of a tropical complaint than is bacillary dysentery, but the latter is also common both in tropical and temperate climates. Both forms are transmitted in much the same way and their symptoms are very similar. Hence from the layman’s point of view no good purpose is served by considering them separately, at least so far as methods of transmission and symptoms go. The treatment of the two forms, however, differs, and to carry out such treatment effectively medical skill is required.
Causes.—Dysentery is conveyed by impure drinking water, contaminated food, infected flies, and possibly also by infected dust. In both forms, but especially in the amœbic variety, the so-called “carrier” plays an important part, because in the latter case the organism produces cysts which are passed by the bowel, and these cysts are frequently found in the dejecta of persons who have suffered from amœbic dysentery and who are either convalescent or possibly in quite good health. If these cysts find their way into food or water and are then swallowed they are capable of developing in the human intestine and producing dysentery. Carriers are also met with in the bacillary form of the disease. Dysentery may be provoked by chills, general debility and exhausting conditions, such as chronic malaria.
Symptoms.—Diarrhœa with pains in the belly, straining and frequent desire to go to stool. The motions soon become small in amount, slimy, lose their natural colour, and contain more or less blood; when there is ulceration of the coats of the bowel, the motions are extremely offensive, and bleeding may be very free. There is heat, tenderness, and bearing down about the outlet of the bowel, with considerable prostration and probably some fever; there is frequently a constant desire to pass water. All these symptoms may be due to severe ordinary diarrhœa; but in the tropics it is best to treat them as if they were dysenteric. Some guide may be obtained as to the form of dysentery from which the patient is suffering by taking his temperature. As a rule there is little or no fever associated with the amœbic form, while in the case of the bacillary type the temperature is always raised and in severe cases may be considerably elevated. It is in this form that the small intestine is apt to become involved and then the condition is more serious.
One help in diagnosis, though not a very reliable one, is the character of the stool. In amœbic dysentery the blood is apt to be mixed with the dejecta and to be dark in colour, while the whole mass looks brown or greyish green. The stool of bacillary dysentery, on the other hand, has a whitish appearance, the blood in it is bright coloured and is often in the form of streaks or spots. The amœbic form is apt, if not promptly and efficiently treated, to be followed by inflammation of the liver, which may go on to liver abscess.
Prophylaxis.—Avoid chill and debilitating causes of all kinds. In countries where there is a great difference between the day and the night temperature wear a cholera belt. Carefully protect food and water from contamination of any kind, and especially from flies. Doubtful water should be boiled or rendered sterile by some chemical method. All milk should be boiled. Care should be taken not to employ as cooks natives who have recently suffered from dysentery, and scrupulous cleanliness should be observed in the preparation of food. Unripe fruit and other materials apt to cause diarrhœa should be avoided. Camp conservancy methods should be carried out on approved sanitary principles which prevent the access of flies to human excrement and prevent the latter from being disseminated by wind or in any other way. All dysenteric stools should be carefully disinfected or burnt.
Treatment.—The general treatment is common to both forms, the essentials being rest, warmth and suitable food. Put the patient to bed, apply a cholera belt and get the bowels open by an initial dose of castor oil. If there is much pain ten drops of tincture of opium may be added to the oil. The usual dose of the oil is an ounce, but if the patient is feeble or exhausted half an ounce will be sufficient.
As regards diet do not give any milk at first, and indeed if the case is recognized as being one of bacillary dysentery milk should not be given at all as it tends to favour putrefaction. Albumin water, rice water, chicken broth are required during the first twenty-four hours. Thereafter in the amœbic form milk diluted with barley water or with citrate of soda (three grains to the ounce) can be given. Soups are often useful, and at a later period custard, arrowroot and jellies are indicated. In the bacillary type arrowroot, meat and fruit jellies and beef-tea can be given from the outset. In both types the food should be given in small quantities frequently, and it should be neither too hot nor too cold. Alcohol is deleterious.
Fortunately we now have a specific drug for treating amœbic dysentery and that is emetine, which is the active principle of ipecacuanha. It is best given in the form of emetine bismuthous iodide, which is supplied in capsules and the dose of which is three grains per day for twelve consecutive days. The dose is best given in the evening along with a cup of hot tea on a full stomach when the patient is in bed. If it causes much vomiting it is well to give ten or fifteen drops of tincture of opium before administering the emetine. The latter can also be given by subcutaneous injection, but this method of treatment should only be carried out by a physician. Where emetine is not available ipecacuanha itself may be used and is given as follows:—