title: The malabsorption of commonly occurring mono and disaccharides: levels of investigation and differential diagnoses.
abstract: BACKGROUND
  Adverse food reactions (AFR) have has recently attracted increased attention from the media and are now more commonly reported by patients. Its classification, diagnostic evaluation, and treatment are complex and present a considerable challenge in clinical practice. Non-immune-mediated types of food intolerance have a cumulative prevalence of 30% to 40%, while true (immune-mediated) food allergies affect only 2% to 5% of the German population.
  
  
  METHODS
  We selectively searched the literature for pertinent publications on carbohydrate malabsorption, with special attention to published guidelines and position papers.
  
  
  RESULTS
  Carbohydrate intolerance can be the result of a rare, systemic metabolic defect (e.g., fructose intolerance, with a prevalence of 1 in 25,000 persons) or of gastrointestinal carbohydrate malabsorption. The malabsorption of simple carbohydrates is the most common type of non-immune-mediated food intolerance, affecting 20% to 30% of the European population. This condition is caused either by deficient digestion of lactose or by malabsorption of fructose and/or sorbitol. Half of all cases of gastrointestinal carbohydrate intolerance have nonspecific manifestations, with a differential diagnosis including irritable bowel syndrome, intolerance reactions, chronic infections, bacterial overgrowth, drug side effects, and other diseases. The diagnostic evaluation includes a nutritional history, an H2 breath test, ultrasonography, endoscopy, and stool culture.
  
  
  CONCLUSIONS
  The goals of treatment for carbohydrate malabsorption are to eliminate the intake of the responsible carbohydrate substance or reduce it to a tolerable amount and to assure the physiological nutritional composition of the patient's diet. In parallel with these goals, the patient should receive extensive information about the condition, and any underlying disease should be adequately treated.
authors.affiliation: Department of Medicine 1 - Gastroenterology, Pneumology and Endocrinology, Universitätsklinikum Erlangen, Gastroenterology practice, Regensburg, Department of Internal Medicine II, Thüringen-Klinik Saalfeld, Dietetics Service, University Hospital Erlangen.
authors.forename: Martin
authors.initials: M
authors.lastname: Raithel
authors.forename: Michael
authors.initials: M
authors.lastname: Weidenhiller
authors.forename: Alexander Fritz-Karl
authors.initials: AF
authors.lastname: Hagel
authors.forename: Urban
authors.initials: U
authors.lastname: Hetterich
authors.forename: Markus Friedrich
authors.initials: MF
authors.lastname: Neurath
authors.forename: Peter Christopher
authors.initials: PC
authors.lastname: Konturek
mesh_terms: D001944:Breath Tests / Q000379:methods*; D002239:Carbohydrate Metabolism, Inborn Errors / Q000145:classification / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004040:Dietary Carbohydrates / Q000009:adverse effects*; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D005243:Feces / Q000737:chemistry*; D006801:Humans; D008286:Malabsorption Syndromes / Q000145:classification / Q000175:diagnosis* / Q000209:etiology; D008487:Medical History Taking / Q000379:methods; D014463:Ultrasonography / Q000379:methods*
chemical_list: D004040:Dietary Carbohydrates