Steatorrhea (orsteatorrhoea) is the presence of excess fatinfeces. Stools may be bulky and difficult to flush, have a pale and oily appearance, and can be especially foul-smelling.[1] 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.[2]
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.[2]
The absence of bile secretion can cause the feces to turn gray or pale. Bile is responsible for the brownish color of feces. In addition to this, bile also plays a role in fat absorption, where dietary lipids are combined so that pancreatic lipases can hydrolyze them before going towards the small intestine. Without bile acids, this pathway would have a hard time occurring, which would lead to fat malabsorption and make steatorrhea more probable to occur.[2] 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.[1]
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.[6][7][8] Vytorin (ezetimibe/simvastatin) tablets can cause steatorrhea in some people.[6][8]
Some studies have shown that stool lipids are increased when whole nuts are eaten, compared to nut butters, oils or flour[9] and that lipids from whole nuts are significantly less well absorbed.[10]
Consuming jojoba oil has been documented to cause steatorrhea and anal leakage because it is indigestible.[11]
Consuming escolar and oilfish (sometimes mislabelled as butterfish) will often cause steatorrhea, also referred to as gempylotoxism or gempylid fish poisoning or keriorrhea.[12]
The fat substitute Olestra, used to reduce digestible fat in some foods, was reported to cause leakage in some consumers during the test-marketing phase. As a result, the product was reformulated before general release to a hydrogenated form that is not liquid at physiologic temperature. The U.S. Food and Drug Administration warning indicated excessive consumption of Olestra could result in "loose stools"; however, this warning has not been required since 2003.[7][13]
Steatorrhea should be suspected when the stools are bulky, floating and foul-smelling.[1] Specific tests are needed to confirm that these properties are in fact due to excessive levels of fat. Fats in feces can be measured over a defined time (often five days).[14] Other tests include the (13)C-mixed triglycerides test and fecal elastase, to detect possible fat maldigestion due to exocrine pancreatic insufficiency,[14] or various specific tests to detect other causes of malabsorption such as celiac disease.[15]
^Dogliotti L, Tampellini M, Stivanello M, Gorzegno G, Fabiani L (2001). "The clinical management of neuroendocrine tumors with long-acting repeatable (LAR) octreotide: comparison with standard subcutaneous octreotide therapy". Annals of Oncology. 12 (Suppl 2): S105–9. doi:10.1093/annonc/12.suppl_2.s105. PMID11762334.
^ abSquires S (2006-01-24). "Weighing a Pill For Weight Loss". Washington Post. Retrieved 2007-07-06. While the Food and Drug Administration (FDA) still must approve the switch, the agency often follows the advice of its experts. If it does, Orlistat (xenical) -- currently sold only by prescription -- could be available over-the-counter (OTC) later this year. But it's important to know that the weight loss that's typical for users of the drug -- 5 to 10 percent of total weight -- will be less than many dieters expect. And many consumers may be put off by the drug's significant gastrointestinal side effects, including flatulence, diarrhea, and anal leakage.
^ ab"Frito-Lay Study: Olestra Causes "Anal Oil Leakage"". Center for Science in the Public Interest. February 13, 1997. Archived from the original on 2016-06-18. Retrieved 2007-07-07. The Frito-Lay report states: "The anal oil leakage symptoms were observed in this study (3 to 9% incidence range above background), as well as other changes in elimination. ... Underwear spotting was statistically significant in one of two low-level consumer groups at a 5% incidence above background." Despite those problems, the authors of the report concluded that olestra-containing snacks "should have a high potential for acceptance in the marketplace."
^ ab"The Word Is 'Leakage'. Accidents may happen with a new OTC diet drug". Newsweek. June 25, 2007. Archived from the original on 2007-06-18. Retrieved 2007-06-21. GlaxoSmithKline has a tip for people who decide to try Alli, the over-the-counter weight-loss drug it is launching with a multimillion-dollar advertising blitz—keep an extra pair of pants handy. That's because Alli, a lower-dose version of the prescription drug Xenical, could (cue the late-night talk-show hosts) make you soil your pants. But while Alli's most troublesome side effect, anal leakage, is sure to be good for a few laughs, millions of people who are desperate to take off weight may still decide the threat of an accident is worth it.
^Place AR (1992). "Comparative aspects of lipid digestion and absorption: Physiological correlates of wax ester digestion". The American Journal of Physiology. 263 (3 Pt 2): R464–71. doi:10.1152/ajpregu.1992.263.3.R464. PMID1415629.
