The anal sphincters, along with the pelvic muscles that surround the end of the digestive tract, ensure controlled movement of digestive tract contents. There are many possible causes of fecal incontinence; in most cases, incontinence results from some combination of these causes. Critical to normal bowel function are:
Oilcloth is a tightly woven fabric, usually cotton or linen, which is then treated on one side to give it a waterproof finish. The coating traditionally was linseed oil, but is now more commercially sold with a PVC coating.
Aluminum and zirconium salts are also used in tanning. Oil tanning is an ancient method that is used for such soft, porous leathers as chamois and deerskin, which can be repeatedly wetted and dried without detrimental effects. Fish oil is sprinkled onto the hides and pounded in with mechanical hammers.