Substance that promotes defecation .
These include irritants (stimulants) such as cascara sagrada and castor oil, bulk formers such as bran and psyllium, saline laxatives such as Epsom salts or milk of magnesia, glycerin, lubricants such as mineral oil and some vegetable oils, and stool softeners. A high-fibre diet is more important than laxatives in correcting simple intestinal constipation.