Rhubarb or Rhei radix (Rheum palmatum L. and Rheum officinale Baillon)
Parts used: dried underground parts
Constituents: hydroxyanthracene derivatives, dianthrone glycosides (sennosides), anthrone glycosides
Pharmacopoeia Standard: root should contain no less than 2.2 per cent of hydroxyanthracene derivatives (rhein)
Actions: laxative, astringent, stomachic
Indications: for short-term use in occasional constipation and conditions in which a soft stool is desirable, e.g. haemorrhoids or anal fissure.
Applications: Generally used in the treatment of constipation, its astringent action also makes it of value in diarrhoea, but at very low doses. Its bitter taste stimulates the digestion.
Safety: Long-term use of any laxative can have serious physiological effects. Excessive intake may result in potassium loss from the body. Not recommended in pregnancy and breastfeeding and contraindicated in cases of intestinal obstruction, atony, inflammatory bowel disease, kidney disorders, abdominal pain of unknown origin and dehydration. Not recommended for children.
Dosage: Generally an ingredient of a compound remedy. As with all laxatives, the correct individual dose is the smallest required to produce a comfortable, soft-formed stool. 
