Updated: 7/12/2019

Malabsorption Syndromes

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Snapshot
  • A 45-year-old woman presents to her primary care physician with a complaints of unintentional weight loss. She denies any fevers or night sweats. She does report having frequent diarrhea as well as pale, foul-smelling bowel movements. She recently went on a trip to the Carribbean. On physical exam, she appears thin but her physical exam is otherwise insignificant. Serum labs reveal increased prothrombin time. A small bowel biopsy shows the presence of PAS-negative microorganisms. She is started on antibiotics. (Tropical sprue)
Introduction
  • Overview
    • malabsorption syndromes
      • inability to absorb macronutrients or micronutrients
      • often associated with chronic diarrhea and result in nutritional deficiencies
    • treatment is targeted at correcting the underlying disorder
  • Epidemiology
    • etiology
      • fat malabsorption
        • celiac disease
        • Whipple disease
          • infection with Tropheryma whipplei
        • pancreatic insufficiency
        • tropical sprue
          • cause unknown but thought to be due to microorganisms in the tropics
      • lactose intolerance
      • bile salt deficiency
      • short bowel syndrome
  • Pathogenesis
    • mechanism
      • impairment in absorption of nutrients due to a variety of defects in intestinal mucosa
      • malabsorption of fat-soluble vitamins
        • vitamins A, D, E, and K
      • vitamin B12 deficiency
        • destruction of terminal ileum
        • loss of pancreatic enzymes that aid in B12 absoprtion
      • lactose intolerance
        • lactase deficiency
        • colonic bacteria ferment lactose and cause decreased stool pH, resulting in osmotic diarrhea
Presentation
  • History
    • easy bruising
  • Symptoms
    • common symptoms
      • frequent and loose watery stools
        • lactose intolerance
      • pale, bulky, foul-smelling stools
        • fat malabsorption
      • abdominal pain and flatus
      • bloating and weight loss
      • vitamin deficiencies
Vitamin Deficiencies
Vitamin A Deficiency
Vitamin D Deficiency
Vitamin E Deficiency
Vitamin K Deficiency
  • Night blindness
  • Xeroderma
  • Osteomalacia
  • Ricketts
  • Hemolytic anemia
  • Muscle weakness
  • Paresthesias
  • Bleeding
  • Easy bruising
 
Imaging
  • Abdominal computed tomography
    • indications
      • evaluate for chronic pancreatitis
Studies
  • Serum labs
    • hypocalcemia
    • ↑ prothrombin time/INR
      • vitamin K malabsorption
    • autoantibodies for celiac disease
    • anemia
      • microcytic or macrocytic depending on etiology of malabsorption syndrome
  • Invasive studies
    • Sudan black stain of stool
      • stains and detects fat
    • 72-hour fecal fat test
      • most sensitive
    • small bowel biopsy
      • indication
        • diagnosis of celiac disease, Whipple disease, or tropical sprue
      • findings
        • celiac disease
          • villous atrophy, crypt hyperplasia, and lymphocytosis
        • Whipple disease
          • PAS-positive organisms with foamy macrophages in intestinal lamina propria
        • tropical sprue
          • microorganisms
        • lactase deficiency
          • normal villi 
    • lactose hydrogen breath test
      • indication
        • lactose intolerance testing
    • D-xylose absorption test
      • indications
        • diagnosis of small intestine malabsorption
        • distinguishes from pancreatic disorders
      • findings
        • abnormal D-xylose testing indicates that villous lining is destroyed or impaired, resulting in malabsorption of D-xylose
Differential
 
Fat Malabsorption Syndromes

Celiac Disease
Whipple Disease Pancreatic Insufficiency Tropical Sprue
Fat malabsorption
  • Pale, bulky, and foul-smelling stools
Unique clinical features
  • Positive autoantibodies
  • Dermatitis herpetiformis
  • Triad
    • cardiac symptoms
    • arthralgia
    • neurologic symptoms
  • Caused by Tropheryma whipplei, a gram-positive rod
  • History of alcoholism
  • History of previous episodes of pancreatitis
  • History of being in tropical regions
  • Negative autoantibodies
  • Megaloblastic anemia due to folate and vitamin B12 deficiences
Diagnostic testing
  • Small bowel biopsy
  • Abnormal D-xylose test
  • Autoantibodies
  • Small bowel biopsy
  • Polymerase chain reaction of stool showing T. whipplei
  • Abnormal D-xylose test
  • Abdominal CT scan
  • Secretin stimulation testing
  • Small bowel biopsy
  • Abnormal D-xylose test
Treatment
  • Dietary restrictions
    • avoid gluten
  • Ceftriaxone
  • Trimethoprim/sulfamethoxazole
  • Tetracycline
  • Enzyme replacement therapy
  • Doxycycline
  • Trimethoprim/sulfamethoxazole
 
Treatment
  • Lifestyle
    • dietary restriction
      • indication
        • celiac disease
      • modality
        • avoid gluten
  • Medical
    • treat underlying condition
    • antibiotics
      • indication
        • whipple disease
        • tropical sprue
      • drugs
        • tetracycline
        • doxycycline
        • ceftriaxone
        • trimethoprim/sulfamethoxazole
    • enzyme replacement therapy
      • indication
        • chronic pancreatitis
        • lactose intolerance
    • nutrition replacement therapy
      • indication
        • vitamin deficiencies
  • Surgical
    • none
Complications
  • Malnutrition
 

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