Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Gastrointestinal Malabsorption article more useful, or one of our other health articles.
Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit https://www.nice.org.uk/covid-19 to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below.
What is gastrointestinal malabsorption?
Gastrointestinal malabsorption is a failure to fully absorb nutrients from the gastrointestinal tract. The digestion and absorption of nutrients within the gastrointestinal tract requires a complex interaction between motor, secretory, digestive and absorptive processes that are vulnerable to various potential disturbances which may lead to global or specific malabsorption syndromes.
The outcome is malnutrition. Malnutrition may also be caused by inadequate diet with or without malabsorption. See also the separate Malnutrition article.
Malabsorption, from whatever cause, may be accompanied by:
- Changes in weight and growth:
- Gastrointestinal symptoms:
- Chronic diarrhoea is common. Chronic diarrhoea may be defined as the abnormal passage of three or more loose or liquid stools per day for more than four weeks and/or a daily stool weight greater than 200 g/day.
- Steatorrhoea is often present. There is excessive fat in the stools and they become pale, bulky and offensive in smell. Stools float and are difficult to flush away. They often leave a greasy rim around the pan.
- Family history:
- Signs of deficiencies may be apparent. There may be:
However the malabsorption of simple carbohydrates is the most common type of non-immune-mediated food intolerance, affecting 20-30% of the European population .
- Coeliac disease usually presents in childhood but can present later.
- Lactose intolerance.
- Cow's milk protein allergy.
- Soya milk intolerance.
- Fructose intolerance and malabsorption: simultaneous consumption of glucose reduces fructose malabsorption .
- In patients with an inflammatory bowel disorder and malabsorption, an immune deficiency, including HIV enteropathy, should be considered.[7, 8]
- Intestinal lymphangiectasia and other causes of lymphatic obstruction include lymphoma, tuberculosis and cardiac disease.
- Pancreatic insufficiency:
- Bile acid malabsorption: defective secretions of bile salts, due to cholestatic jaundice or disease of the terminal ileum.
- Small intestinal bacterial overgrowth (SIBO).
- Intestinal hurry:
- The blind loop syndrome involves disturbance of normal gut flora with malabsorption.
- Diverticulae and strictures.
- Crohn's disease.
- Short bowel syndrome.
- Eosinophilic gastroenteropathy.
- Mesenteric arterial insufficiency.
- Radiation enteritis.
Causes outside the gut
- Addison's disease.
- Diabetes mellitus.
- Carcinoid syndrome.
- Widespread skin disease (rapid cell turnover may also affect gut mucosa).
- Collagen diseases.
- Eating disorders.
- Factitious diarrhoea due to purgative abuse.
- Plasma viscosity, ESR, CRP.
- Vitamin B12 level.
- Red cell folate.
- Iron status (usually ferritin but can be iron and iron-binding capacity).
- Clotting screen for vitamin K deficiency.
- Serum albumin.
- Calcium (corrected for albumin level).
- Magnesium, zinc, phosphorous.
- Vitamin D.
- Anti-endomysial, anti-reticulin and alpha-gliadin antibodies (coeliac screen).
- Faecal microbiological assessments may be indicated.
- Sudan stain for fat globules.
- Tests for secretory function - eg, elastase or chymotrypsin in stool.
Imaging and endoscopy
- Abdominal ultrasound (gallbladder, liver, pancreas, intestinal wall, adenopathy).
- Barium follow-through may show structural abnormalities.
- Jejunal biopsy (and aspirate for possibility of SIBO).
- Ileocolonoscopy including biopsies of colon and ileum.
- CT; MRI of pancreatic duct-systems or endoscopic retrograde cholangiopancreatography (ERCP).
Breath hydrogen tests
Take samples of end-expired air; give glucose; take more samples at half-hourly intervals. If there is bacterial overgrowth there is an increase in exhaled hydrogen one hour after ingestion.
Nutritional support may be required for malabsorption.
Management otherwise depends upon the cause. For example:
- Coeliac disease requires a strict gluten-free diet.
- Pancreatic insufficiency requires the oral administration of enzymes with food.
- Blockage of the flow of bile requires surgery.
- Crohn's disease usually responds to steroids.
- Blind loop syndromes may require further surgery.
- Where bile salts are not reabsorbed, it may be necessary to give resins to bind them.
- If there is folate deficiency and possibly B12 deficiency too, it is imperative to give an injection of vitamin B12 before starting folate supplementation. Otherwise, there is a risk of precipitating subacute combined degeneration of the cord.
Complications are related to the underlying disease.
Further reading and references
Zuvarox T, Belletieri C; Malabsorption Syndromes. StatPearls, July 2021.
Keller J, Layer P; The Pathophysiology of Malabsorption. Viszeralmedizin. 2014 Jun30(3):150-4. doi: 10.1159/000364794.
Davis J, Kellerman R; Gastrointestinal Conditions: Malabsorption Syndromes. FP Essent. 2022 May516:31-37.
Ghoshal UC, Mehrotra M, Kumar S, et al; Spectrum of malabsorption syndrome among adults & factors differentiating celiac disease & tropical malabsorption. Indian J Med Res. 2012 Sep136(3):451-9.
Raithel M, Weidenhiller M, Hagel AF, et al; The malabsorption of commonly occurring mono and disaccharides: levels of investigation and differential diagnoses. Dtsch Arztebl Int. 2013 Nov 15110(46):775-82. doi: 10.3238/arztebl.2013.0775.
Burgers K, Lindberg B, Bevis ZJ; Chronic Diarrhea in Adults: Evaluation and Differential Diagnosis. Am Fam Physician. 2020 Apr 15101(8):472-480.
Latulippe ME, Skoog SM; Fructose malabsorption and intolerance: effects of fructose with and without simultaneous glucose ingestion. Crit Rev Food Sci Nutr. 2011 Aug51(7):583-92. doi: 10.1080/10408398.2011.566646.
Agarwal S, Mayer L; Gastrointestinal manifestations in primary immune disorders. Inflamm Bowel Dis. 2010 Apr16(4):703-11. doi: 10.1002/ibd.21040.
Murray JA, Rubio-Tapia A; Diarrhoea due to small bowel diseases. Best Pract Res Clin Gastroenterol. 2012 Oct26(5):581-600. doi: 10.1016/j.bpg.2012.11.013.
Hackert T, Schutte K, Malfertheiner P; The Pancreas: Causes for Malabsorption. Viszeralmedizin. 2014 Jun30(3):190-7. doi: 10.1159/000363778.
Achufusi TGO, Sharma A, Zamora EA, et al; Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods. Cureus. 2020 Jun 2712(6):e8860. doi: 10.7759/cureus.8860.
Ensari A; The Malabsorption Syndrome and Its Causes and Consequences. Pathobiology of Human Disease. 2014 : 1266–1287.
Johnston I, Nolan J, Pattni SS, et al; New insights into bile acid malabsorption. Curr Gastroenterol Rep. 2011 Oct13(5):418-25. doi: 10.1007/s11894-011-0219-3.