Dysentery Entry, Transcription from the Ship’s Captain’s Medical Guide, 1868 p. 46-47:

Dysentery [sic]

This disease is almost entirely confined to the crews of ships trading to China and the East Indies; sometimes, but much more rarely, it occurs in those coming from the West Indies, west coast of Africa, South America, and some of the Mediterranean ports, particularly Alexandria and Odessa.
The symptoms are well known to most captains:-
Looseness of the bowels, with much straining, stools more or less bloody, resulting in great general weakness.
In nine-tenths of the cases that occur in East India and China ships, the sailors will tell you that they had dysentery in the country before sailing, and this probably for some weeks. If such a history be made out satisfactorily, you must let your patient have as much rest as possible, give him slop diet, continue his limejuice, let him have 10 grains of Dover’s powder three times a day, 10 drops of laudanum in an ounce of castor oil every third say, and plenty of warmth to the body. Leave off the limejuice at the end of a week for a few days only if it appears to aggravate the disease...[Y]ou will find that, when temperate latitudes are reached, your patient will almost invariably improve ; and you may then give him 2 grains of quinine three times a day for several weeks. Arrowroot, sago, flour, rice, or any other light extras that you may have, are always well expended on such cases. If, however, you are perfectly satisfied that the disease has commenced for the first time in a man after the ship has put to sea, pursue the same directions as to diet, knock off all his limehuice , and instead of Dover’s powder, give 5 grains of ipecacuanha powder three times a day, gradually increasing the dose to 10 or 15 grains if no vomiting occur. If your patient does not improve under this treatment, give him his limejuice again, and pursue the same plan as that first recommended. It must be recollected , however, that it India and China very few cases of dysentery commence after leaving port, the vast majority being cases where the disease has begun during the sailor’s stay in the country.
No other patients that may come under your care will so well repay all possible indulgence that you can give in the matter of rest when ill, and easy deck work when improving.