Malabsorption occurs when there is a disruption in the normal digestion and absorption of nutrients in the small intestine. It can cause symptoms like diarrhea, weight loss, and malnutrition. There are several potential causes of malabsorption, including celiac disease, Whipple's disease, bacterial overgrowth, short bowel syndrome, and lactase deficiency. Celiac disease is an immune-mediated reaction to gluten that damages the small intestine and is treated with a gluten-free diet. Whipple's disease is a rare infection caused by Tropheryma whippelii that presents with weight loss and joint pain and is treated with long-term antibiotics. Bacterial overgrowth in the small intestine can also interfere with absorption

1. MalabsorptionPatrick Carter MPAS, PA-CFebruary 7, 2011Clinical Medicine I

2. ObjectivesList and describe the 3 phases of normal digestion and absorption.Discuss the normal process of digestion and absorption including anatomical locations of absorption for:VitaminsCarbohydratesFatsProtein

3. ObjectivesDefine malabsorptionDescribe the following in terms of etiology, epidemiology, risk factors, signs and symptoms, diagnostic work-up, treatment, and complications:Celiac diseaseWhipple’s Bacterial overgrowth Compare and contrast the causes of short bowel syndrome, and discuss the resulting malabsorptions from each cause.Describe lactase deficiency in terms of etiology, epidemiology, risk factors, signs and symptoms, diagnostic work-up, and treatment.

4. Normal DigestionFunctions of intestinal epitheliumNutrient digestion and absorptionBarrier and immune defenseFluid and electrolyte balanceProduction of proteins, amines, and peptides

5. Normal DigestionThree phases of digestionIntraluminal phase (digestive)Dietary fats, proteins and carbohydrates are hydrolyzed and solubilized by pancreatic and biliary secretionMucosal phase (absorptive)Occurs in small intestine by brush border enzymesDelivery phase (post-absorptive)Dysfunction in this stage can lead to significant protein losses

6. MalabsorptionDisruption of digestion and nutrient absorptionSigns and symptomsSteatorrheaDiarrheaWeight loss, malnutritionIron deficiency anemia/megaloblastic anemia

7. MalabsorptionSigns and symptomsBone pain and fracturesParesthesia and tetanyBleeding problemsEdemaMilk intoleranceNocturia; abdominal distention

8. MalabsorptionDiagnostic testingLabs – CBC, PT, alkphos, CMP, folate, B12, iron, amylase, lipaseFecal fatUpper endoscopy with biopsyBarium study of the small bowel

9. Celiac DiseaseAKA celiac spruePermanent dietary disorder caused by an immunologic response to glutenThe disease is present in 1:100 caucasians of Northern European descentOnly 60% of those will have symptoms

10. Celiac DiseaseSymptomsChildren < 2 yearsChronic diarrhea, steatorrhea, weight loss, abdominal distention, weakness, muscle wasting or growth retardation Children >2 years and adultsChronic diarrhea, dyspepsia, or flatulence+/- weight lossMany have no GI symptoms but present with fatigue, depression, Fe def anemia, osteoporosis, short stature, delayed puberty or reduced fertility

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12. Celiac DiseaseSignsPE may be normalMalabsorption signs – loss of muscle mass or subcutaneous fat, pallor, easy bruising (vit K def), bone pain or neurologic signs (vit B12 or E def)Abdominal exam – may reveal distention with hyperactive bowel sounds

13. Celiac DiseaseDermatitis herpetiformisa cutaneous form of celiac diseasePruriticpapulovesicles over the extensor surfaces of the extremities and over the trunk, scalp and neckOccurs in <10% of patients with celiac disease

14. Dermatitis Herpetiformis

15. Celiac DiseaseLaboratory findingsMicrocytic anemia or megaloblastic anemia on CBCLow calcium or elevated alkphosIncreased prothrombin timeSpecific testsStool for fecal fatSerologic tests for celiac diseaseIgAendomysial antibody and IgAtTG antibody

16. Celiac DiseaseSpecial tests (cont’d)Endoscopic mucosal biopsy of the distal duodenum or proximal jejunumConfirms the diagnosis in pt with positive serologic testsDifferential diagnosisIBSBacterial overgrowthLactose intolerance

17. Celiac DiseaseTreatmentGluten-free diet (wheat, rye, barley)Clinical improvement on gluten-free diet after a few weeksDietary supplements (folate, iron, Ca, Vit A, B12, D and E) should be provided in the initial stages of therapyPrognosis – excellent once diagnosed

18. Whipple’s DiseaseRare multisystemic illness caused by infection with the bacillus TropherymawhippeliiCommonly affects white men 30 – 50 years oldSource of infection is unknownWill not spread human-to-human

19. Whipple’s DiseaseSymptomsWeight loss (most common presenting symptom)Arthalgias or migratory non-deforming arthritisGI symptoms – abdominal pain, diarrhea, malabsorption, flatulence, steatorrheaIntermittent low-grade feverSignsEnteric protein loss with edema and hypoalbuminemiaGeneralized LADEnlarged and warm peripheral joints

20. Whipple’s DiseaseSigns (cont’d)Ocular symptoms (uveitis, retinitis, etc.)Congestive heart failure or valvular regurgitationDiagnostic studiesLabs may show malabsorptionDiagnosis is made by endoscopic biopsy of the duodenum showing the Whipple bacillus

21. Whipple’s DiseaseDifferential diagnosisOther malabsorptive conditionsFUOCeliac sprueMycobacterium avium complex (MAC) infectionSarcoidosis and other autoimmune diseases

22. Whipple’s DiseaseTreatment Antibiotic therapy for at least one yearIV Rocephin (ceftriaxone) 2 g daily for 2 weeks Bactrim DS (TMP-SMX) 1 po bid for 1 yearDoxycycline if allergic to sulfaPrognosisFatal if untreatedPatients must be followed closely for recurrence

23. Bacterial OvergrowthOvergrowth damages mucosa of small intestine and interferes with absorptionCauses of overgrowthGastric achlorhydriaAnatomic abnormalities with stagnationMotility disordersGastrocolic or coloenteric fistula

24. Bacterial OvergrowthSigns and symptomsMost patients are asymptomaticS/S of malabsorption – distention, weight loss and steatorrhea or watery diarrheaDiagnostic testingFecal fatAspiration and culture of proximal jejunum secretions (invasive)Lactose breath test (noninvasive)

25. Bacterial OvergrowthTreatmentCorrection of anatomic defect if neededBroad-spectrum antibiotics for 1-2 weeksCipro 500 mg PO bidAmoxicillin clavulanate 875 mg PO bidMay need cyclic antibiotic therapy (1 week out of every 4 weeks)

26. Short Bowel SyndromeMalabsorptive condition that arises secondary to removal of significant segments of small intestineCrohn’s diseaseMesenteric infarctionTraumaRadiation enteritisTumor resectionTraumaCan usually tolerate resection of 40-50% of the small intestine

27. Short Bowel SyndromeTerminal ileum resectionMalabsorption of bile salts and B12Treatment is low-fat diet, cholestyramine, and vitaminsExtensive small bowel resectionWeight loss and diarrheaTreatmentParenteral vitamin and mineral supplementationLperamide – slows transit and reduces diarrheal volumeTPN in most severe cases

28. Lactase DeficiencyLactase is a brush border enzyme that hydolyzes lactose into glucose and galactoseLactase enzyme levels decline with age in most people of non-European ancestry50 million Americans95% of Native Americans90% of Asian Americans70% of African Americans60% of Jewish Americans 50% of Mexican Americans<25% Caucasian Americans

29. Lactase DeficiencyFoods high in lactoseMilk (12g/cup)Ice cream (9g/cup)Cottage cheese (8g/cup)Aged cheeses (0.5g/cup)

30. Lactase DeficiencySigns and symptomsVary with severity of deficiency and amount of lactose ingestedMost can drink one or two 8 oz glasses of mild daily without symptoms, if taken with food and at wide intervalsBloating, abdominal cramps, flatulence and diarrhea after lactose ingestionNo weight lossLaboratory findingsHydrogen breath test

31. Lactase DeficiencyDifferential diagnosisIBDMalabsorptive disordersIBSTreatmentGoal is patient comfortLimit lactose containing foods to threshold Lactase enzyme replacement (Lactaid)

32. Questions?