Steatorrhea (or steatorrhoea) is the presence of excess fat in feces. Stools may be bulky and difficult to flush, have a pale and oily appearance, and can be especially foul-smelling. An oily anal leakage or some level of fecal incontinence may occur. There is increased fat excretion, which can be measured by determining the fecal fat level. The definition of how much fecal fat constitutes steatorrhea has not been standardized. Causes Impaired digestion or absorption can result in fatty stools. Possible causes include exocrine pancreatic insufficiency, with poor digestion from lack of lipases, loss of bile salts, which reduces micelle formation, and small intestinal disease-producing malabsorption. Various other causes include certain medicines that block fat absorption or indigestible or excess oil/fat in diet. The absence of bile secretion can cause the feces to turn gray or pale. Bile is responsible for the brownish color of feces. Other features of fat malabsorption may also occur such as reduced bone density, difficulty with vision under low light levels, bleeding, bruising, and slow blood clotting times. Associated diseases Conditions affecting the pancreas. Exocrine pancreatic insufficiency can be caused by chronic pancreatitis, cystic fibrosis and pancreatic cancer (if it obstructs biliary outflow). Conditions affecting bile salts. Obstruction of the bile ducts by gallstones (choledocholithiasis), primary sclerosing cholangitis, liver damage (intrahepatic cholestasis), hypolipidemic drugs, or changes following gallbladder removal (cholecystectomy). Conditions producing intestinal malabsorption. These include celiac disease, bacterial overgrowth, tropical sprue, Giardiasis (a protozoan parasite infection), Zollinger-Ellison syndrome, short bowel syndrome, inflammatory bowel disease and abetalipoproteinemia. Other causes: Drugs that can produce steatorrhea include orlistat, a slimming pill, or as adverse effect of octreotide or lanreotide, used to treat acromegaly or other neuroendocrine tumors. It can be found in Graves' disease / hyperthyroidism. Medications Orlistat (also known by trade names Xenical and Alli) is a diet pill that works by blocking the enzymes that digest fat. As a result, some fat cannot be absorbed from the gut and is excreted in the feces instead of being metabolically digested and absorbed, sometimes causing oily anal leakage. Vytorin (ezetimibe/simvastatin) tablets can cause steatorrhea in some people. Excess whole nuts in diet Some studies have shown that stool lipids are increased when whole nuts are eaten, compared to nut butters, oils or flour and that lipids from whole nuts are significantly less well absorbed. Natural fats Consuming jojoba oil has been documented to cause steatorrhea and anal