Fecal fat test 593400 191507538 2008-02-14T21:47:57Z WhatamIdoing 1998764 moved [[Fecal fat]] to [[Fecal fat test]] over redirect: Complete name In [[medicine]], a '''fecal fat''' test is a diagnostic test for [[fat]] [[malabsorption]] conditions (also referred to as [[steatorrhea]]). ==Background== In the [[small intestine]], dietary fat (primarily [[triglyceride]]s) is digested by [[enzyme]]s such as [[pancreatic lipase]] into smaller molecules which can be absorbed through the wall of the small intestine and enter the [[Circulation (physiology)|circulation]] for [[metabolism]] and storage. As [[fat]] is a valuable nutrient, human [[feces]] normally contain very little undigested fat. However, a number of diseases of the pancreas and gastrointestinal tract are characterized by fat malabsorption. Examples of such diseases are: * disorders of exocrine [[pancreas|pancreatic]] function, such as [[chronic pancreatitis]], [[cystic fibrosis]] and [[Shwachman-Diamond syndrome]] (these are characterized by deficiency of pancreatic digestive enzymes) * [[celiac disease]] (in which the fat malabsorption in severe cases due to inflammatory damage to the integrity of the intestinal lining) * [[short bowel syndrome]] (in which much of the small intestine has had to be surgically removed and the remaining portion cannot completely absorb all of the fat). *[[small bowel bacterial overgrowth syndrome]] ==Microscopy== In the simplest form of the fecal fat test, a random fecal specimen is submitted to the [[hospital laboratory]] and examined under a [[microscope]] after [[staining]] with a [[Sudan III]] or [[Sudan IV]] dye ("[[Sudan stain]]ing"). Visible amounts of fat indicate some degree of fat malabsorption.. ==Quantitative fecal fat test== Quantitative fecal fat tests measure and report an amount of fat. This usually done over a period of three days, the patient collecting all of their feces into a container. The container is thoroughly mixed to homogenize the feces, this can be done with a [[paint mixer]]. A small sample from the feces is collected. The fat content is extracted with [[solvent]]s and measured by [[saponification]] (turning the fat into [[soap]]). Normally up to 7 [[gram]]s of fat can be malabsorbed in people consuming 100 grams of fat per day. In patients with [[diarrhea]], up to 12 grams of fat may be malabsorbed since the presence of diarrhea interferes with fat absorption, even when the diarrhea is not due to fat malabsorption. {{Unreferenced|date=August 2007}} [[Category:Gastroenterology]] [[Category:Feces]] [[Category:Stool tests]]