Psyllium or Ispaghula is the common name used for several members of the plant genus Plantago whose seeds are used commercially for the production of mucilage. Psyllium is mainly used as a dietary fiber, which is not absorbed by the small intestine. The purely mechanical action of psyllium mucilage absorbs excess water while stimulating normal bowel elimination. Although its main use has been as a laxative, it is more appropriately termed a true dietary fiber and as such can help reduce the symptoms of both constipation and mild diarrhea. Psyllium is produced mainly for its mucilage content, which is highest in P. ovata. The term mucilage describes a group of clear, colorless, gelling agents derived from plants. The mucilage obtained from psyllium comes from the seed coat. Mucilage is obtained by mechanical milling/grinding of the outer layer of the seed. Mucilage yield amounts to about 25% (by weight) of the total seed yield. Plantago-seed mucilage is often referred to as husk, or psyllium husk. The milled seed mucilage is a white fibrous material that is hydrophilic, meaning that its molecular structure causes it to attract and bind to water. Upon absorbing water, the clear, colorless, mucilaginous gel that forms increases in volume by tenfold or more. The United States is the world's largest importer of psyllium husk, with over 60% of total imports going to pharmaceutical firms for use in products such as "Metamucil". In Australia, psyllium husk is used to make "Bonvit" psyllium products. In the UK, ispaghula husk is used in the popular constipation remedy "Fybogel". In India, psyllium husk is used to make "Gulab Sat Isabgol" psyllium products. Psyllium mucilage is also used as a natural dietary fiber for animals. The dehusked seed that remains after the seed coat is milled off is rich in starch and fatty acids, and is used in India as chicken feed and as cattle feed. Psyllium mucilage possesses several other desirable properties. As a thickener, it has been used in ice cream and frozen desserts. A 1.5% weight/volume ratio of psyllium mucilage exhibits binding properties that are superior to a 10% weight/volume ratio of starch mucilage. The viscosity of psyllium mucilage dispersions are relatively unaffected between temperatures of 20Â°C and 50Â°C (68 to 122Â°F), by pH from 2 to 10 and by salt (sodium chloride) concentrations up to 0.15 M. These physical properties, along with its status as a natural dietary fiber, may lead to increased use of psyllium by the food-processing industry. Technical-grade psyllium has been used as a hydrocolloidal agent to improve water retention for newly-seeded grass areas, and to improve transplanting success with woody plants.