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.
It often relieves hunger, by arresting the secretion of gastric j uice and the movements of the stomach and bowel,'* and it frequently upsets digestion from the same cause.
Lower down in the bowel these compounds are converted into ferrous sulphide and tannate, and are eliminated with the faeces, turning them black.
The third theory is that of Bunge, who says that in chlorotic conditions there is an excess of sulphuretted hydrogen in the bowel, changing the food iron into sulphide of iron, which Bunge states cannot be absorbed.
Commencing in and around the solitary glands of the large intestine in the form of exudations, these ulcers, small at first, enlarge and run into each other, till a large portion of the bowel may be implicated in the ulcerative process.
When iron is injected directly into a vein it depresses the heart's action, the blood pressure and the nervous system, and during its excretion greatly irritates the bowel and the kidneys.
- Sulphur itself has no action, but when brought into contact with the secretions it forms sulphides, sulphites and sulphuretted hydrogen, and thereby becomes more or less irritant and antiseptic. In the bowel its conversion into sulphides causes it to act as a mild laxative.
When dissolved in water, however, carbonic acid gas is a gentle stimulant to the mouth, stomach and bowel, the mixture being absorbed more rapidly than plain water; hence its greater value in assuaging thirst.
Intermittent and remittent fevers are very prevalent; bowel complaints are common, and often fatal in the autumn.
The universal custom of sleeping on the house-top in summer promotes rheumatic and neuralgic affections; and in the Koh Daman of Kabul, which the natives regard as having the finest of climates, the mortality from fever and bowel complaint, between July and October, is great, the immoderate use of fruit predisposing to such ailments.
Similarly the beneficial effects of purgation may be due not only to the elimination which takes place through the bowel, but also to the internal secretion from the intestinal glands.
For this purpose solutions of sulphate of copper or of nitrate of silver may be gently introduced into the bowel in quantities of a quart at a time.
The last acts chiefly upon the lower bowel, and forms a constituent of nearly every purgative pill.
Latterly, free irrigation of the bowel with astringents, such as silver nitrate, tannalbin, &c., has been attended with success in those cases which have been able to tolerate the injections.
They may be applied externally as fomentations, for the relief of tormina; by rectal injection for the relief of the tenesmus and irritability of the bowel; hypodermically in advanced cases, for the relief of the general distress.
Mercury and lead are absorbed from the bowel in considerable quantities, and are capable of inducing acute irritant poisoning as well as chronic poisoning.
Substances like pepper, cayenne pepper, mustard, horse-radish and ginger irritate the stomach and bowel much in the same way, but are more pungent, and are consequently used as condiments.
The large number of vegetable substances used as purgatives owe their action to an irritating effect upon the mucous membrane and the neuro-muscular apparatus of the bowel, whereby the secretions and peristalsis are more or less increased, as the result of which diarrhoea ensues.
Some of them cause so much irritation that the discharge is very watery (hydragogue cathartics), while others, for example aloes, by acting gently on the lower part of the bowel and on its muscular coat, produce simply a laxative effect.
It has in addition a markedly depressing action upon the respiratory centre, it lessens all the secretions except the sweat, and diminishes bowel peristalsis and the size of the pupil.
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.
In certain rare cases the whole of the stomach has been removed, the bowel being brought up and spliced to the end of the gullet.
Sometimes a gall-stone which has found its way into the intestine is large enough to block the bowel and give rise to intestinal obstruction which demands abdominal section.
Their aperient action is dependent upon the minimum of irritation of the bowel, and is exercised by their abstraction from the blood of water, which passes into the bowel to act as a diluent of the salt.
The stronger the solution administered, the greater is the quantity of water that passes into the bowel, a fact to be borne in mind when the salt is administered for the purpose of draining superfluous fluid from the system, as in dropsy.
The amount of iron existing in the human blood is only 38 gr.; therefore, when an excess of iron is absorbed, part is excreted immediately by the bowel and kidneys, and part is stored in the liver and spleen.
In large doses oil of turpentine causes purging and may induce much haemorrhage from the bowel; it should be combined with some trustworthy aperient, such as castor oil, when given as an anthelmintic. It is readily absorbed unchanged and has a marked contractile action upon the blood vessels.