|Classification and external resources|
|Specialty||Gastroenterology, general surgery|
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.
Dietary fats and lipids are usually efficiently digested and over 90% absorbed. 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 including 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. 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.
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, sometimes causing oily anal leakage. Vytorin (ezetimibe/simvastatin) tablets can cause steatorrhea in some people.
There are anecdotal reports on the internet describing oily droplets in feces after eating large amounts of cashews or other whole nuts. They agree with studies showing that stool lipids are greatest when whole nuts are eaten, compared to their nut butters, oils or flour and that lipids from whole nuts are significantly less well absorbed.
Consuming escolar and oilfish (sometimes called butterfish) will often cause steatorrhea, also referred to as Gempylotoxism or Gempylid Fish Poisoning or keriorrhea. The fish is commonly used in party catering[where?] due to its delicate flavor and because it is cheap and readily available.
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.
Treatments are mainly correction of the underlying cause, as well as digestive enzyme supplements.
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.
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."
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, milions of people who are desperate to take off weight may still decide the threat of an accident is worth it.
Olestra sometimes causes underwear staining associated with "anal leakage." Olestra sometimes causes underwear staining. That phenomenon may be caused most commonly by greasy, hard-to-wipe-off fecal matter, but occasionally also from anal leakage (leakage of liquid olestra through the anal sphincter).