Here’s the second part to Dr. Medora’s explanation of laxatives. More varieties of vegetable laxatives are explored, including prunes, laxative resins, and sugar alcohols.
Miscellaneous Vegetable Laxatives
Laxative Resins: Podophyllum resin is extracted from the roots and rhizomes of mayapple Podophyllum peltatum L. (Fam: Berberidaceae), a plant indigenous to the Eastern U.S. The Jalap resin is obtained from the roots and rhizomes of Ipomoea purga Hayne (Fam: Convolvulaceae), a plant indigenous to Mexico, while the colocynth resin is found in the fruits of Citrullus colocynthis Schrader (Fam: Cucurbitaceae).6 These resins have a very drastic cathartic action and hence their use in the U.S. has been discontinued.
Prunes: Prunes are dried plums obtained from the fruits of Prunus domestca L. (Fam: Rosaceae). Prunes are believed to produce their laxative effect due to higher amounts of soluble fiber present in them. Prune juice, however, contains no fiber and its laxative effect is sometimes believed to be due to sugars or an uncharacterized compound called isatin. Ironically, despite the generally recognized laxative effect of both prunes and prune juice, an FDA Advisory Panel on stimulant laxatives did not find sufficient evidence to confirm their safety and efficacy as OTC drugs, and classified them as ineffective laxatives in 1990.
They are classified as hyperosmotic laxatives. Glycerol is administered as a laxative in the form of glycerin suppositories and is a laxative of choice for children under the age of six. Sorbitol and lactulose are often used as mild laxatives in the elderly patients.