This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Upon the alimentary tract, antimony acts as an irritant in greater or less degree, according to the dose: 1/30 to 1/15 gr. of the tartrate, or even less when repeated, will induce some sense of warmth in the stomach, and some increase of its secretions; 1/8 to 1/4 gr. will cause, in addition, a feeling of soreness, a flow of saliva, impairment of appetite, and possibly nausea; 3/4 to 1 gr., given in a glass of water, will usually induce vomiting within fifteen to thirty minutes. The vomiting is distressing in character, accompanied with shivering, much depression, retching, and persistent nausea: the ejecta contain mucus, and later, bile. The same dose generally purges, and if taken with a large quantity of water will be almost sure to do so, either with or without vomiting. The evacuations at first are simply fluid, then mixed with free bile, and are passed with some straining and griping pain. It is noteworthy that a larger close is required to produce these effects when given by intravenous injection than by the stomach.
Large doses of 10 to 20 gr. or more, act very severely; the local irritation and burning pain are great; vomiting occurs quickly and with much distress; there is difficulty in swallowing, spasm of oesophagus, severe tenesmus and cramp in the abdominal muscles, and profuse diarrhoea of sero-albuminous fluid, containing flocculi of detached epithelium (like the rice-water stools of cholera), and sometimes blood.
In fatal cases the mucous membrane of the stomach and of parts of the intestine, especially the lower portions and the rectum, has been found acutely congested or inflamed, softened, aphthous, or ulcerated.