This section is from the book "A Practitioner's Handbook Of Materia Medica And Therapeutics", by Thos. S. Blair. Also available from Amazon: A Practitioner's handbook of Materia Medica and Therapeutics.
Colocynthis. This is a peculiar drug, long misunderstood. The official Extractum Colocvnthidis is a reliable preparation for its usual employment. The ec. tr. is too violent in action. The mother tincture is a 10% preparation of the pulp of the dried fruit freed from outer rinds and seed. I would advise the extract for its purgative effect and @ for small doses.
If the ec. tr. is used at all it should be diluted with nine volumes of 76% alcohol and used as the tincture. In large doses colocynth is a hydrogogue cathartic, very violent in action, and should not be given in the presence of feebleness or inflammation. The average dose of the extract is 1/2 gr., and in this dose, or even I gr. doses, it is safe and often useful. In small doses it is useful in sharp, cutting pain and cramp in the bowels. The form of colic bending one double and relieved by pressure. This sounds like homeopathy, but it is really nothing of the sort, because it is not diarrhea but temporary neuralgic pain that small doses of colocynth cures. It has the same effect in uterine neuralgia of a transient nature, and also in temporary sciatica. Enteralgia, gastralgia, neurotic pains and tenesmus is its field. In infantile colic use @, 5 I. in half-glass of water, and give a teaspoonful every fifteen minutes. For adults use somewhat larger doses, usually I or 2 I, @, at a dose. Colocynth cannot be classed with the usual "cramp and colic" cures. It is not a direct remedy for diarrhea, but it is a remedy giving quick relief from pain within its indications.