Malabsorption
Malabsorption: Excerpt from The 5-Minute Pediatric Consult
Gabriel Arancibia, MD
Maria R. Mascarenhas, MBBS
Malabsorption - BASICS
Malabsorption - description
Malabsorption is a syndrome, not a disease entity and is defined as any state in which there is a disturbance of digestion and/or absorption of nutrients across the intestinal mucosa. Malabsorption is characterized by the association of chronic diarrhea, abdominal distention, and failure to thrive.
Malabsorption - epidemiology
It depends on the underlying disease causing malabsorption.
Malabsorption - pathophysiology
- According to the nutrient affected:
- Carbohydrate:
- Monosaccharide: Congenital glucose-galactose deficiency, fructose intolerance
- Disaccharide: Lactase deficiency (congenital or acquired), sucrase-isomaltase deficiency
- Polysaccharide: Amylase deficiency (congenital or acquired)
- Fat:
- Bile salt deficiency: Cholestasis, resection of terminal ileum
- Exocrine pancreatic insufficiency: Cystic fibrosis, chronic pancreatitis
- Inadequate surface area: Celiac disease, flat villous lesion
- Protein:
- Protein-losing enteropathy: Intestinal lymphangiectasia, congenital heart failure
- Exocrine pancreatic insufficiency: Cystic fibrosis, Shwachman syndrome
- Inadequate surface area: Celiac disease
- According to the place where the alteration occurs:
- Mucosal abnormality:
- Anatomical: Post-enteritis syndrome, celiac disease, IBD
- Functional: Disaccharidase deficiencies
- Luminal abnormality:
- Exocrine pancreatic insufficiency: Cystic fibrosis, Shwachman-Diamond syndrome
- Bile salt insufficiency: Biliary cholestatic liver disease, ileal resection
- Anatomical abnormality:
- Short gut: Surgical resection
- Motility disturbance: Intestinal pseudo-obstruction
Malabsorption - etiology
The most common causes of malabsorption in developed countries are:
- Postenteritis syndrome
- Cow’s milk protein intolerance
- Giardiasis
- Celiac disease
- Cystic fibrosis
- Inflammatory bowel disease (IBD)
Malabsorption - DIAGNOSIS
Malabsorption - signs & symptoms
Malabsorption - history
- GI symptoms:
- GI symptoms are common in patients with malabsorption syndromes and range from mild abdominal gaseous distention to severe abdominal pain and vomiting. Chronic or recurrent diarrhea is by far the most common symptom.
- Abdominal distention and watery diarrhea, with or without mild abdominal pain associated with skin irritation in the perianal area due to acidic stools are characteristic of carbohydrate malabsorption syndromes.
- Fat malabsorption can present with bulky foul smelling stools that are oily and float. Abdominal distension, increased gas, weight loss, and increased appetite are also seen.
- Periodic nausea, abdominal distention and pain, and diarrhea are common in patients with chronic Giardia infections.
- Vomiting, with moderate-to-severe abdominal pain and bloody stools, is characteristic of protein sensitivity syndromes.
- Malabsorption syndromes can definitely cause abdominal pain or irritability (particularly seen in celiac disease).
- Stool characteristics:
- Frequent loose watery stools may indicate carbohydrate intolerance.
- Bulky, greasy or loose foul-smelling stools indicate fat malabsorption.
- In protein malabsorption, stools may be normal or loose.
- Bloody stools are seen in patients with cow’s milk protein allergy, infection, and inflammatory bowel disease.
- Other symptoms:
- Malabsorption of carbohydrates, fats, or proteins can cause failure to thrive.
- Anemia, with weakness and fatigue due to inadequate absorption of vitamin BEdema due to decreased protein absorption and hypoalbuminemia
- Muscle cramping due to decreased vitamin D causing hypocalcemia, and decreased potassium levels
Malabsorption - physical exam
- In the absence of GI tract symptoms, malabsorption syndromes should be considered during the workup for failure to thrive, malnutrition, poor weight gain, or delayed puberty.
- Malabsorption syndromes should be suspected in infants with weight loss or little weight gain since birth and in infants with low weight and weight-for-height percentiles.
- Malnutrition symptoms may be present, as reduced SC fat, paleness, angular cheilosis and muscle weakness. It is often to find abdominal distension, increased bowel sounds, and rash around mouth and anus.
Malabsorption - tests
Malabsorption - lab
- Stool analysis:
- The presence of reducing substances and pH <5.5 indicates that carbohydrates have not been properly absorbed.
- The level of quantitative stool fat and the amount of fat intake in the diet should be measured and monitored for three days and a coefficient of fat absorption calculated using the following formula: Grams of ingested fat—grams of fat in stool/grams of ingested fat × 100. Normal values for the coefficient of fat absorption: >93% in children and adults, >85% in infants, >67% in premature infants. Moderate fat malabsorption ranges from 60–80%. Fat absorption of <50% indicates severe malabsorption.
- The presence of large serum proteins in the stool, such as alpha-1-antitrypsin, indicates leakage of serum protein. A 24-hour stool collection for alpha-1-antitrypsin (along with a serum level) serves as a screening test for protein-losing enteropathy.
- Examination of the stool for ova and parasites or testing for the stool antigen may reveal the presence of Giardia species.
- Normally, stool bile acids should not be detected. If bile acid malabsorption is suspected, quantitative conjugated and unconjugated bile acids may be measured in stool, although this test is not routinely available and is not used in routine clinical practice.
- Other laboratory studies:
- CBC may reveal anemia in patients with iron, folate and vitamin BTotal serum protein and albumin levels may be lower than reference range in syndromes in which protein is lost or is not absorbed, particularly in protein-losing enteropathy and pancreatic insufficiency.
- With fat malabsorption or ileal resection, fat-soluble vitamin levels in the serum are low.
- With bile acid malabsorption, levels of the low-density lipoprotein cholesterol may be low.
- Serum calcium may be low due to vitamin D and amino acid malabsorption
- Serum vitamin A, E, and carotene may be low due to bile salt deficiency and impaired fat absorption.
- Other studies must be performed when a specific disease is suspected, as mucosal biopsy for celiac disease, sweat test for cystic fibrosis or appropriate workup for IBD.
- Urine analysis should be done to rule out proteinuria in patients with low albumin levels.
Malabsorption - differencial diagnosis
- Postenteritis syndrome
- Cow’s milk protein intolerance
- Giardiasis
- Celiac disease
- Cystic fibrosis
- Inflammatory bowel disease (IBD)
Malabsorption - TREATMENT
- The treatment will depend on the underlying disease causing malabsorption. Appropriate nutritional support is of paramount importance.
- Specific treatment depends on etiology, for example, glutenfree diet for celiac disease, metronidazol for Giardia infection, or removal of the offending agent in a case of food intolerance.
Malabsorption - FOLLOW UP
Malabsorption - complications
Complications vary according to the underlying disease, but malnutrition and its consequences may worsen progressively if the cause is not determined and appropriate treatment prescribed. Some of the most frequent complications of malabsorption and malnutrition are: Growth failure, vitamins and micronutrient deficiency (zinc, magnesium, calcium), bone disease, hypoproteinemia and edema, essential fatty acid deficiency, perianal dermatitis, immune dysfunction and anemia.
Malabsorption - bibliography
- Dodge JA, Turck D. Cystic fibrosis: Nutritional consequences and management. Best Pract Res Clin Gastroenterol. 2006;20(3):531–546.
- Fasano A, Catassi C. Celiac disease in children. Best Pract Res Clin Gastroenterol. 2005;19(3):467–478.
- Crittenden RG, Bennett LE. Cow’s milk allergy: A complex disorder. J Am Coll Nutr. 2005;24(6 Suppl):582S–591S.
- Ali SA, Hill DR. Giardia intestinalis. Curr Opin Infect Dis. 2003;16(5):453–460.
Malabsorption - CODES
Malabsorption - icd9
- 271.3 Intestinal disaccharidase deficiencies and disaccharide malabsorption
- 579 Intestinal malabsorption
- 579.9 Unspecified intestinal malabsorption
Malabsorption - FAQ
- Q: When should a patient with malabsorption be referred?
- A: Children with growth failure in whom malabsorption is suspected should be referred to a pediatric gastroenterologist because of the associated high morbidity.
- Q: What is the prognosis of malabsorption?
- A: Some malabsorption syndromes are transient, while others simply require a change in diet. Most disorders that cause secondary malabsorption are progressive and, because of systemic complications, result in a significant morbidity.
>>
Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
More About Malabsorption
More Medical Textbooks Online about Malabsorption
Review other book chapters online related to Malabsorption:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
|
|
More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
|
|
» Next page: Surveys relating to Malabsorption
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
