It acts in about five hours, affecting the entire length of the bowel, but not increasing the flow of bile except in very large doses.
Its combined action on the bowel and the uterus is of especial value in chlorosis, of which amenorrhoea is an almost constant symptom.
In some cases of chronic inflammation of the kidneys, where the disease is not extensive, the patient may continue in fair health for a number of years, provided attention be paid to the following rules: - (i) The body must be kept warm, and chills must be scrupulously avoided; (2) the digestion must be attended to carefully, so that no excess of poisonous bodies is formed in the intestine or absorbed from it; (3) eliminating channels such as the skin and bowel must be kept active.
Lower down in the bowel these compounds are converted into ferrous sulphide and tannate, and are eliminated with the faeces, turning them black.
In larger doses colchicum or colchicine acts as a most violent gastrointestinal irritant, causing terrible pain, colic,vomiting, diarrhoea, haemorrhage from the bowel, thirst and ultimately death from collapse.