Steatorrhea overview

# Overview
Steatorrhea is the formation of non-solid feces. Stools may also float due to excess fat from malabsorption, have an oily appearance and be 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. While definitions have not been standardized, fat excretion in feces in excess of 0.3 (g/kg) / day is considered indicative of steatorrhea. Based on underlying etiology steatorrhea can be classified into 3 types, intestinal, biliary, and pancreatic steatorrhea.  Steatorrhea occurs as a result of either defect of the normal architecture of digestive tract or defect of synthesis or secretion of enzymes required for metabolism fats. Steatorrhea may be caused by Celiac disease, choledocholithiasis, cystic fibrosis, exocrine pancreatic insufficiency, hypolipidemic drugs, inflammatory bowel disease, small bowel bacterial overgrowth syndrome. Common risk factors in the development of steatorrhea include Celiac disease, cystic fibrosis, exocrine pancreatic insufficiency, inflammatory bowel disease, small intestinal bacterial overgrowth, hypolipidemic drugs. If left untreated, steatorrhea can lead to severe malnutrition due to inability of gastrointestinal tract to absorb fat soluble vitamins and ultimately severe weight loss. Complication of steatorrhea include anemia, intestinal obstruction, weight loss. Prognosis of steatorrhea is generally good with appropriate treatment. The 72 hr-fecal fat determination is the gold standard test for the diagnosis of steatorrhea. Mild steatorrhea can manifest as passage of frothy, foul smelling stool, greasy in appearance and difficult to flush, abdominal pain, bloating, heart burn. if severe it may cause malnutrition , dehydration, anemia, muscle weakness, weight loss, skin problems, neurological problems, osteoporosis. Patients with steatorrhea usually appear emaciated secondary to loss of subcutaneous fat. Physical examination of patients with steatorrhea is usually remarkable for distended abdomen, orthostatic hypo-tension and ecchymoses, Chvostek sign and Trousseau sign secondary to hypocalcemia. There are no specific laboratory findings associated with steatorrhea. Management of steatorrhea include treatment of underlying etiology, control of diarrhea and correction of nutritional deficiencies. Surgery is usually reserved for patients with refractory or pre-malignant complications, such as Enteropathy Associated T-cell Lymphoma (EATL) and ulcerative jejunitis (UJ).  Effective measures for the primary prevention of steatorrhea include smoking cessation, alcohol cessation, minimizing the use of certain medications, such as antibiotics, that can alter normal bowel flora, and consuming diet rich in dietary fiber.

# Historical Perspective
The history of celiac disease dates back to late 1800's when an english scientist described celiac disease. In October 1887, Samuel Gee, a pediatrician, was the first to describe in detail celiac disease and its association with fatty stools. In 1950, Wim Dicke's colleagues, Weijers and Van de Kamer, presented a way to diagnose mal-absorption syndromes by using stool fat measurement. In late 1960's case of idiopathic steatoeehea and reticulosis of the small bowel as a late complication was reported.

# Classification
Steatorrhea may be classified based on etiology into 3 types, intestinal, biliary, and pancreatic steatorrhea.

# Pathophysiology
Stearorhea can be defined as loss of undigested fat in stools. The processes can be invoked by either defect of the normal architecture of digestive tract or it may involve defect of synthesis or secretion of enzymes of GI tract which are needed to metabolize fatty content of food.

# Causes
Steatorrhea may be caused by Celiac disease, choledocholithiasis, cystic fibrosis, exocrine pancreatic insufficiency, hypolipidemic drugs, inflammatory bowel disease, small bowel bacterial overgrowth syndrome.

# Differentiating steatorrhea from other Diseases
Steatorrhea must be differentiated from other causes of mal-absorption such as cystic fibrosis, Hartnup'sdisease, Whipple's disease, Zollinger Ellison syndrome, acrodermatitis enteropathica, intestinal lymphangiectasia.

# Epidemiology and Demographics
The demographic measures of steatorrhea can be explained by independent causes of steatorrhea.

# Risk Factors
Common risk factors in the development of steatorrhea include: Celiac disease, cystic fibrosis, exocrine pancreatic insufficiency, inflammatory bowel disease, small intestinal bacterial overgrowth, hypolipidemic drugs

# Screening
There is insufficient evidence to recommend routine screening for steatorrhea

# Natural History, Complications, and Prognosis
If left untreated, steatorrhea can lead to severe malnutrition due to inability of gastrointestinal tract to absorb fat soluble vitamins and  ultimately severe weight loss. Complication of steatorrhea include anemia, intestinal obstruction, weight loss. Prognosis of steatorrhea is generally good with appropriate treatment.

# Diagnosis

## Diagnostic study of choice
The 72 hr-fecal fat determination  is the gold standard test for the diagnosis of steatorrhea

## History and Symptoms
Mild steatorrhea can manifest as passage of frothy, foul smelling stool, greasy in appearance and difficult to flush, abdominal pain, bloating, heart burn. if severe it may cause malnutrition , dehydration,anemia, muscle weakness, weight loss, skin problems, neurological problems, osteoporosis.

## Physical Examination
Patients with steatorrhea usually appear emaciated secondary to loss of subcutaneous fat. Physical examination of patients with steatorrhea is usually remarkable for distended abdomen, orthostatic hypo-tension and ecchymoses, Chvostek sign and Trousseau sign secondary to hypocalcemia.

## Laboratory Findings
Quantitative analysis of fat in the stool may be helpful in the diagnosis of steatorrhea. The various tests that may be helpful in the diagnosis are acid steatocrit, near-infrared reflectance analysis (NIRA) and sudan III stain.

## Imaging Findings

## X-ray
There are no x-ray findings associated with steatorrhea. However, there are x-ray findings depends on the underlying causes.

## CT scan
There are no CT scan findings associated with steatorrhea. However, there are CT scan findings depends on the underlying causes

## MRI
There are no MRI findings associated with steatorrhea. However, there are MRI findings depends on the underlying causes.

## Other Diagnostic Studies
There are no other diagnostic studies associated with steatorrhea. However, there are no other diagnostic studies depends on the underlying causes.

# Treatment

## Medical Therapy
Management of steatorrhea include treatment of underlying etiology, control of diarrhea and correction of nutritional deficiencies.

## Surgery
Surgical intervention is usually not recommended for the management of steatorrhea. Surgery is usually reserved for patients with refractory or pre-malignant complications, such as Enteropathy Associated T-cell Lymphoma (EATL) and ulcerative jejunitis (UJ). EATL patients presenting with ulcerative lesions, stenotic lesions, and perforation needs surgical intervention. Surgery also serves as a pre-therapy in order to prevent perforation of the small bowel during chemotherapy in case of EATL. After surgery patients receive immunotherapy, chemotherapy and/or stem cell transplantation

## Primary Prevention
Effective measures for the primary prevention of steatorrhea include smoking cessation, alcohol cessation, minimizing the use of certain medications, such as antibiotics, that can alter normal bowel flora, and consuming diet rich in dietary fiber.

## Secondary Prevention
Secondary preventive measures of steatorrhea are similar to primary preventive measures.