Steatorrhea (or steatorrhoea) is the presence of excess

fat In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food. The term often refers specifically to triglycerides (triple est ...

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 Fecal incontinence (FI), or in some forms encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents, both liquid stool elements and mucus, or solid feces. When this loss includes flatus (gas), it is referre ...

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 Lipase ( ) is a family of enzymes that catalyzes the hydrolysis of fats. Some lipases display broad substrate scope including esters of cholesterol, phospholipids, and of lipid-soluble vitamins and sphingomyelinases; however, these are usually tr ...

, loss of

bile salts Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Diverse bile acids are synthesized in the liver. Bile acids are conjugated with taurine or glycine residues to give anions called bile salts. Primary b ...

, which reduces micelle formation, and small intestinal disease-producing

malabsorption Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a variety ...

. 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 The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an en ...

. Exocrine pancreatic insufficiency can be caused by chronic

pancreatitis Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancr ...

, cystic fibrosis and pancreatic cancer (if it obstructs biliary outflow). * Conditions affecting

. Obstruction of the

bile ducts A bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates. Bile is required for the digestion of food and is secreted by the liver into passages that carry bile toward the hepatic duct. It ...

gallstones A gallstone is a stone formed within the gallbladder from precipitated bile components. The term cholelithiasis may refer to the presence of gallstones or to any disease caused by gallstones, and choledocholithiasis refers to the presence of mi ...

(

choledocholithiasis Common bile duct stone, also known as choledocholithiasis, is the presence of gallstones in the common bile duct (CBD) (thus '' choledocho-'' + ''lithiasis''). This condition can cause jaundice and liver cell damage. Treatments include choledocholi ...

), primary sclerosing cholangitis, liver damage (intrahepatic

cholestasis Cholestasis is a condition where bile cannot flow from the liver to the duodenum. The two basic distinctions are an obstructive type of cholestasis where there is a mechanical blockage in the duct system that can occur from a gallstone or malig ...

), hypolipidemic drugs, or changes following

gallbladder In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although ...

removal ( cholecystectomy). * Conditions producing intestinal

. These include

celiac disease Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine, where individuals develop intolerance to gluten, present in foods such as wheat, rye and barle ...

, bacterial overgrowth,

tropical sprue Tropical sprue is a malabsorption disease commonly found in tropical regions, marked with abnormal flattening of the villi and inflammation of the lining of the small intestine. It differs significantly from coeliac sprue. It appears to be a more ...

, Giardiasis (a protozoan parasite infection), Zollinger-Ellison syndrome,

short bowel syndrome Short bowel syndrome (SBS, or simply short gut) is a rare malabsorption disorder caused by a lack of functional small intestine. The primary symptom is diarrhea, which can result in dehydration, malnutrition, and weight loss. Other symptoms may in ...

, inflammatory bowel disease and

abetalipoproteinemia Abetalipoproteinemia (also known as: Bassen-Kornzweig syndrome, microsomal triglyceride transfer protein deficiency disease, MTP deficiency, and betalipoprotein deficiency syndrome) is a disorder that interferes with the normal absorption of fat ...

. * Other causes: Drugs that can produce steatorrhea include

orlistat Orlistat, sold under the brand name Xenical among others, is a medication used to treat obesity. Its primary function is preventing the absorption of fats from the human diet by acting as a lipase inhibitor, thereby reducing caloric intake. It ...

, a slimming pill, or as adverse effect of octreotide or

lanreotide Lanreotide, sold under the brand name Somatuline among others, is a medication used in the management of acromegaly and symptoms caused by neuroendocrine tumors, most notably carcinoid syndrome. It is a long-acting analogue of somatostatin, like ...

, used to treat acromegaly or other

neuroendocrine tumors Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly occur in the intestine, where they are often called carcinoid tumors, but they are also found in the pancreas, lun ...

. It can be found in Graves' disease /

hyperthyroidism Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidis ...

Medications

Orlistat Orlistat, sold under the brand name Xenical among others, is a medication used to treat obesity. Its primary function is preventing the absorption of fats from the human diet by acting as a lipase inhibitor, thereby reducing caloric intake. It ...

(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 Jojoba oil is the liquid produced in the seed of the ''Simmondsia chinensis'' ( jojoba) plant, a shrub, which is native to southern Arizona, southern California, and northwestern Mexico. The oil makes up approximately 50% of the jojoba seed by w ...

has been documented to cause steatorrhea and anal leakage because it is indigestible. Consuming

escolar The escolar, ''Lepidocybium flavobrunneum'', a species of fish in the family Gempylidae, is found in deep (200–885 metres, or 656–2,904 ft) tropical and temperate waters around the world. It is also known as snake mackerel, ' ( Hawaii ...

and

oilfish The oilfish (''Ruvettus pretiosus'') is a species of snake mackerel fish with a cosmopolitan distribution in tropical and temperate oceans. It can be found at depths of from , usually between . It can grow to a length of TL (nearly 10 feet) ...

(sometimes mislabelled as butterfish) will often cause steatorrhea, also referred to as Gempylotoxism or Gempylid Fish Poisoning or

keriorrhea Keriorrhea is the production of greasy, orange-colored stools which results from the consumption of indigestible wax esters found in oilfish and escolar. See also * Steatorrhea * Rectal discharge Rectal discharge is intermittent or continu ...

Artificial fats

The fat substitute

Olestra Olestra (also known by its brand name Olean) is a fat substitute that adds no calories to products. It has been used in the preparation of otherwise high-fat foods thereby lowering or eliminating their fat content. The Food and Drug Administrati ...

, 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 The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

warning indicated excessive consumption of Olestra could result in "loose stools"; however, this warning has not been required since 2003.

Diagnosis

Steatorrhea should be suspected when the stools are bulky, floating and foul-smelling. 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). Other tests include the (13)C-mixed triglycerides test and fecal

elastase In molecular biology, elastase is an enzyme from the class of ''proteases (peptidases)'' that break down proteins. In particular, it is a serine protease. Forms and classification Eight human genes exist for elastase: Some bacteria (includin ...

, to detect possible fat maldigestion due to exocrine pancreatic insufficiency, or various specific tests to detect other causes of

such as

Treatment

Treatments are mainly correction of the underlying cause, as well as digestive enzyme supplements.

References

External links

{{Authority control Feces Diarrhea Gastrointestinal tract disorders Diseases of intestines Conditions diagnosed by stool test Symptoms and signs: Digestive system and abdomen Colorectal surgery Steatorrhea-related diseases