Senna has always been specifically used for constipation. It is particularly appropriate when a soft stool is required, for example, in cases of anal fissure. The sennosides irritate the lining of the large intestine, causing the muscles to contract strongly, resulting in a bowel movement about 10 hours after the dose is taken. They also stop fluid from being absorbed from the large bowel, helping to keep the stool soft.

As a cathartic, senna can cause griping and colic, and is therefore normally taken with aromatic, carminative herbs that relax the intestinal muscles.

Leaves and powder are stronger in action than the pods and are not as commonly used. Senna pods, or the dried, ripe fruits, are milder in their effects than the leaflets, as the griping is largely due to the resin, and the pods contain none, but have about 25 per cent more cathartic acid and emodin than the leaves, without volatile oil.

From 6 to 12 pods for the adult, or from 3 to 6 for the young or very aged, infused in a claretglass of cold water, act mildly but thoroughly upon the whole intestine. Similar in action to cascara sagrada, their slightly different chemistry does produce a few differences in action. Whereas cascara is not activated until it reaches the intestines, senna glycosides are readily released by microflora of the stomach and it is about two thirds more active a laxative than cascara.

The pods are made into tablets and other preparations. Senna is very unpleasant tasting and it is best to combine senna pods with aromatic, carminative herbs to increase palatability and reduce griping, e.g. cardamom, ginger or fennel.

Properties:

stimulant, laxative, cathartic

Remedies;

Decoction: for constipation, steep 3-6 senna pods and 1 g fresh ginger in 1 cup freshly boiled water for 6-12 hours. Strain and drink.

Infusion: for mild constipation, infuse 1-2 senna pods, 1 g fresh ginger, and 1-2 cloves in 1 cup freshly boiled water for 15 minutes. Strain and drink

Tincture: prescribed by herbalists to treat shortterm constipation

Toxicity:

Senna is a good short-term laxative but should not be taken for more than 10 days since this leads to weakening of the large bowel muscles. Pregnant and nursing women should not take senna. It should not be used by those with chronic gastrointestinal conditions, such as ulcers, colitis, or hemorrhoids. Drug Interactions: May antagonize antidiarrheal drugs.

Potassium loss caused by chronic use/abuse may potentiate cardiac glycosides and affect antiarrhythmic agents. Thiazide diuretics, cortico-adrenal steroids and licorice root may further deplete potassium. Senna, due to its cathartic activity, may potentiate anticoagulant therapy by reducing absorption of vitamin K from the gut. The herb may also inhibit absorption of dextrose from the intestines. As a cathartic, senna may also increase intestinal transit time of digitalis glycosides, inhibiting their absorption and cardiac action.