1. Malabsorption syndrome
By:
Dr. Elias S.
Dr. Maruf A

2. Malabsorption Impaired absorption of one or more dietary nutrients
A pathophysiologic state with multiple etiologies/varied clinical manifestations
Dietary nutrient absorption –in small b.
Ca., iron, folic acid – absorbed in proximal SB
Cobalamine, bile acid – in the ileum
Glucose, a.a., lipids – throughout the SB
Malabsorption could be:
Primary (congenital defects)
Secondary (acquired defects)
Clinical Sx usually due to:
Malabsorption of fat &/or carbohydrate (with water & electrolyte Mal.)
Steatorrhea  main feature in most cases

3. Diarrhea Nutrient Intestinal malabsorption secretion Steatorrhea
Watery D.
Inflammatory D.
Inflammation

4. mechanisms Luminal phase (processing defect) Mucosal phase
Digestive enzyme deficiency / inactivation
bile salt synthesis; Excretion; loss; bile salt de-conjugation
gastric acid; intrinsic factor (p. anemia)
Bacterial consumption of nutrients
Mucosal phase
Epithelial transport defect – inflammations infections
Brush border hydrolysis defect congenital/acquired disacharidase deficiency
Post-absorptive phase
Enterocyte processing – Abetalipoproteinemia
Lymphocytic obstruction – intestinal lymphangectasia

5. causes
Exocrine pancreatic insufficiency ch. Pancreatitis pancreatic CA cystic fibrosis
Inactivation of pancreatic lipase – Gastrinoma(ZES) drugs (orlistat)
bile acid (impaired micelle formation) parenchymal liver D. cholestatic liver D.
Bacterial overgrowth Anatomic stasis (blind loop,stricture,fistula) Functional stasis (DM, scleroderma)
Interrupted interohepatic circulation of bile acid (ileal resection, crohn’s D.)
Drugs(bind or precipitate bile salt) neomycin, chlestyramine
Impaired mucosal absorbtion/ mucosal loss or defect intestinal resection or bypass inflammation/infiltration/infect. (celiac sprue, tropical sprue, whippl’s disease, lymphoma, mastocytosis, eosinophilic e., scleroderma, crohn’s D., …)
Impaired nutrient transport lymphatic obstruction (lymphoma, lymphangectasia) CHF
Genetic disorders disacharidase defficiency Agamaglobulinemia Abetalipoprotinemia
Endocrine/Metabolic disorders DM
Hyperthyroidism adrenal insufficiency
carcinoid syndrome

6. Clinical features Depend on the cause and severity
Glabal
Diffuse mucosal involvement
Impaired absorption of all nutrients
Classic manifestation Diarrhea(steatorrhea) weight loss
Majority – sub clinical
E.g.. Celiac disease
Partial (isolated)
2° to diseases that interfere with absorption of specific nutrients E.g.Pernicious Anemia Lactase deficiency

7. Signs & symptoms Calori Weight loss with normal appetite Fat
Pale,voluminous,greasy offensive diarrhea
Protein
Edema, muscle atrophy, amenorrhea
carbohydrate
Abdominal bloating, flatus, w. diarrhea
B12
Macrocytic anemia
Subacut combined degeneration of sp.cord
Folic acid
Vit B (general)
Cheliosis, glossitis,A.stomatitis, Acrodermatitis
Iron
Microcytic anemia
Ca & Vit D
Osteomalacea (bone pain,pathologic#), Tetany
Vit A
Follicular hyperkeratosis, Night blindness
VIt K
Bleeding diathesis, Hematoma

8. Clinical Evaluation In 75-80% of cases
Dx by expert Hx & P/E + focused lab tests
25% - need extensive study/ Hospitalization
Hx: -
Diarrhea- duration, consistency, frequency stool characteristics, Volume time of occurrence, association with diet etc….
Bloating,borborigmi, flatus
Abdominal pain
Sxs of extra intestinal manifestation (joint pain, mouth ulcer..)
Previous abd. Surgery
medication
Alcohol intake
Recurrent PUD
DM , CLD
Falmily Hx – celiac disease, crohn’s D.)
Risk factors – HIV infection

9. P/E – thorough examination
Look for signs of specific nutrient Malabsorption extraintestinal signs
Lab.
CBC, PT, serum protein, ALP
Checks for depletion of iron,folate, B12, Vit D, Vit K)
RFT,electrolytes
Stool exam
Additional tests:
Serum carotene, cholesterol, albumin, iron, folate cobalamine

10. Tests for steatorrhea Quantitative test Qualitative tests
72hr stool fat collection – gold standard
> 6gm/day – pathologic
P’ts with steatorrhea - >20gm/day
Modest elevation in diarrheal disease (may not necessarily indicate Malabsorption)
Qualitative tests
Sudan lll stain
Detect clinically significant steatorrhea in >90% of cases
Acid steatocrit – a gravimetric assay
Sensitivity – 100%, specificity – 95% , PPV – 90%
NIRA (near infra reflectance analysis)
Equally accurate with 72hr stool fat test
Allows simultaneous measurement of fecal fat, nitrogen, CHO

11. Schilling test To determine the cause of cobalamine(B12) malabsorbtio
Helps to asses the integrity of gastric, pancreatic and ileal functions.
Abnormal cobalamine absorbtion in: pernicious anemia, ch. Pancreatitis, Achlorohydria, Bacterial overgrowth, ileal dysfunction
The test
Administering 58Co-labeled cobalamine p.o.
Cobalamine 1mg i.m. 1hr after ingestion to saturate hepatic binding sites
Collecting urine for 24 hr (dependant on normal renal & bladder function)
Abnormal - <10% excretion in 24 hrs

12. Schilling test cont…. With Intrinsic factor pancreatic enzyme 5 Days
58Co-Cbl
With
Intrinsic
factor
pancreatic
enzyme
5 Days
Of Ab
Pernicious
Anemia  N
Chronic
Pancreatitis
Bacterial
overgrowth
Ileal disease

13. D-xylose test D-xylose The test
A Pentose monosacharide absorbed exclusively at the proximal SB
Used to asses proximal SB mucosal function
The test
After overnight fast, 25gm D-xylose p.o.
Urine collected for next 5 hrs
Abnormal test - <4.5 gm excretion show duodenal / jejunal mucosal D.
False +ve results: Renal dysfunction Inadequate urine sample
Impaired gastric empyting, ascitis
Drugs(ASA,indometacin, Neomycin)

14. Othe tests for carbohydrate malabsorbtion
Lactose tolerance test
P.o. 50gm lactose
Bloood glucose at 0,60,120 min.
BG <20mg/l + dev’t of Sxs – diagnostic
Breath tests (hydrogen,4Co2,13Co2)
Test for bacterial overgrowth
Quantitative bacterial count from aspirated SB. Normal count: < 10/ml (jejunum) > 10/ml (ileum)
Tests for pancreatic insufficiency
Stimulation of pancreas through adm. Of a meal or hormonal secretagogues , then analysis of duodenal fluid
Indirect tests – schilling test
Tests for protein malabsorption Enteral protein loss  measuring alpha-1 antitirypsin clearance

15. Endoscopy Gross morphology – gives diagnostic clue
Cobblestone appearance – crhon’s D.
Reduced duodenal folds and scallopng of duodenal mucosa – celiac disease
Use of vital dyes to identify villous atrophy
Biopsy – to establish Dx
For p’ts with documented steatorrhea or ch. Diarrhea
Lesions seen – classifid in to three
Diffuse,specific e.g. whippl’s Disease
Patchy, specific – crohn’s D., lymphoma infectious causes
Diffuse,non-specific – celiac sprue, Tropical sprue autoimmune enteropathy
Suspected distal pathology - push enteroscopy wireless capsule endoscopy

17. Barium studies
Important information about the gross anatomy and morphology of SB
Upper GI series with SB follow through
Enteroclysis
double contrast study by passing a tube into proximal SB and injecting barium+ methylcellulose
Normal study doesn’t exclude SB disease