MEDICAL HINTS. 
239 
Purgatives may be divided into the following classes:— 
1. Laxatives. 
2. Simple purgatives. ^ 
3. Drastic purgatives or cathartics. 
4. Saline purges. 
1. Laxatives slightly stimulate the movements of the bowel, but cause 
practically no increase of the intestinal secretion. Examples of this 
class are fruit, wholemeal bread, small doses of castor oil, figs, prunes, 
etc. These may be given regularly in slight cases of chronic con¬ 
stipation. 
2. Simple purges are more powerful than laxatives, and in addition 
to stimulating the movements of the bowel increase the secretion. 
The result is a soft, easy motion. Examples: rhubarb, senna, cascara 
sagrada. 
3. Drastic purgatives or cathartics. The drugs cause a profuse flow 
of the intestinal secretions, and, occasionally, of the bile, with greatly 
increased bowel movements. They cause a copious watery evacuation^ 
accompanied by a good deal of griping. Examples: calomel, colocynth,, 
aloes, podophyllin, croton oil, jalap and oil of turpentine; of these,, 
podophyllin and aloes cause an increase in the flow of bile, with 
increased intestinal.movements, so they may be said to act directly upon 
the liver. The result is a profuse, watery, bile-stained motion. 
Calomel does not act directly upon the liver, but stimulates the upper 
part of the bowel, so that its contents are hurried along before the bile 
can be reabsorbed, and a loose, watery, bile-stained motion ensues. 
The most useful purgative of this class is the pill containing colocynth,, 
calomel, and hyoscamus, of which five to tea grains should be given 
when there is a furred tongue, constipation, heaviness or weight over the 
liver, and dyspepsia and loss of appetite. 
4. Saline purgatives. These cause a free secretion of the intestinal 
juices, and a copious motion, proportionate to the size of the dose, is 
the result. The principal saline purges are Epsom salts (Le., sulphate 
of magnesia), seidlitz powder, the various forms of fruit salts, and the 
aperient mineral waters, such as Eubinat, Hunyadi Janos, etc. 
A saline purgative may be given in the morning, to assist the action of 
an aperient pill administered the previous night. 
