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Malabsorption syndromes
Malabsorption syndromes are conditions characterized by inadequate absorption of nutrients from the intestinal tract. The most common causes include celiac disease, chronic pancreatitis, and less commonly tropical sprue and Whipple disease. Patients typically present with chronic diarrhea, steatorrhea (fatty stools), weight loss, and signs of nutritional deficiencies. Diagnosis involves stool studies, serologic tests, and small bowel biopsy when indicated. Treatment focuses on addressing the underlying cause and correcting nutritional deficiencies.
Last updated: July 29, 2025
- Malabsorption: Impaired absorption of nutrients due to defects in digestion, absorption, or transport
- Maldigestion: Impaired breakdown of nutrients (often grouped with malabsorption)
- Results in deficiency of macronutrients (fats, proteins, carbohydrates) and micronutrients (vitamins, minerals)
- Celiac disease (gluten-sensitive enteropathy) - Most common cause
- Chronic pancreatitis → pancreatic enzyme deficiency
- Tropical sprue → occurs in tropical regions
- Whipple disease → infection with Tropheryma whipplei
- Lactose intolerance → lactase deficiency
- Small intestinal bacterial overgrowth (SIBO)
- Short bowel syndrome → surgical resection
- Medications: orlistat, cholestyramine
General Symptoms
- Steatorrhea: Fatty, greasy, floating stools with foul odor
- Chronic diarrhea
- Weight loss (despite adequate food intake)
- Abdominal bloating and distension
- Flatulence
Signs of Nutritional Deficiencies
| Common Vitamin & Mineral Deficiencies and Their Clinical Manifestations | |
|---|---|
| Deficiency | Clinical Manifestations |
| Vitamin A | Night blindness, xerophthalmia |
| Vitamin D | Osteomalacia, rickets, hypocalcemia |
| Vitamin E | Peripheral neuropathy, ataxia |
| Vitamin K | Easy bruising, prolonged PT/INR |
| Vitamin B12 | Megaloblastic anemia, neuropathy |
| Folate | Megaloblastic anemia |
| Iron | Microcytic anemia |
| Calcium | Tetany, paresthesias |
Initial Tests
- CBC: Anemia (microcytic or macrocytic)
- Serum albumin: Low (protein malabsorption)
- PT/INR: Prolonged (vitamin K deficiency)
- Serum calcium, phosphate: Low
- Vitamin levels: B12, folate, vitamin D
Specific Tests
- 72-hour fecal fat test: Gold standard for steatorrhea
- Sudan stain: Screening test for fecal fat
- D-xylose test: Distinguishes mucosal disease from pancreatic insufficiency
- Small bowel biopsy: Definitive for celiac disease, tropical sprue, Whipple disease
- Serologic tests:
- Anti-tissue transglutaminase (tTG) IgA → celiac disease
- Anti-endomysial antibodies → celiac disease
| Differential Diagnosis of Malabsorption Disorders | ||
|---|---|---|
| Disease | Key Features | Diagnostic Test |
| Celiac Disease |
|
|
| Chronic Pancreatitis |
|
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| Tropical Sprue |
|
|
| Whipple Disease |
|
|
- Treat underlying cause:
- Celiac disease → Gluten-free diet
- Chronic pancreatitis → Pancreatic enzyme replacement
- Tropical sprue → Antibiotics (tetracycline) + folate
- Whipple disease → Antibiotics (ceftriaxone, then TMP-SMX)
- Lactose intolerance → Lactose restriction
- Nutritional supplementation:
- Fat-soluble vitamins (A, D, E, K)
- Iron, B12, folate
- Calcium, magnesium
- Symptomatic treatment:
- Antidiarrheals (if appropriate)
- Medium-chain triglycerides (MCT oil)
- 💡 Steatorrhea = fatty, foul-smelling, floating stools
- 💡 Most common cause = Celiac disease
- 💡 Fat-soluble vitamins = A, D, E, K (remember: "ADEK")
- 💡 Celiac disease → tTG IgA antibodies + villous atrophy
- 💡 D-xylose test: Normal in pancreatic insufficiency, abnormal in mucosal disease
- 💡 72-hour fecal fat = Gold standard for diagnosis