Cause of Malabsorption	Key Features, Tests & Management
Coeliac Disease	😣 Diarrhoea, weight loss, bloating, dermatitis herpetiformis 🧪 Anti-tTG antibodies, small bowel biopsy 💊 Gluten-free diet + vitamin/mineral supplementation
Lactose Intolerance	💨 Bloating, diarrhoea, flatulence after dairy 🧪 Hydrogen breath test, elimination diet 🥛 Lactose-free diet, lactase enzyme supplements
Chronic Pancreatitis	🍽️ Steatorrhea, weight loss, fat-soluble vitamin deficiency 🧪 Faecal elastase, CT/MRCP 💊 Pancreatic enzyme replacement, analgesia, vitamin supplements
Small Intestinal Bacterial Overgrowth (SIBO)	💨 Bloating, diarrhoea, nutrient deficiencies 🧪 Hydrogen breath test, jejunal aspirate culture 💊 Antibiotics (rifaximin), dietary modification
Crohn's Disease	😣 Diarrhoea, pain, malnutrition, anaemia 🧪 Colonoscopy + biopsy, MRI enterography, faecal calprotectin 💊 Steroids, immunomodulators, biologics; surgery if severe
Tropical Sprue	🌴 Chronic diarrhoea, fatigue, nutritional deficiencies 🧪 Small bowel biopsy, folate/B12 blood tests 💊 Antibiotics (tetracyclines), folic acid supplements
Cystic Fibrosis	🫁 Chronic cough, steatorrhea, malnutrition 🧪 Sweat chloride, genetic testing, faecal elastase 💊 Enzyme replacement, nutrition support, chest physio
Whipple's Disease	⚠️ Diarrhoea, steatorrhea, weight loss, arthritis, neuro features 🧪 Small bowel biopsy, PCR for T. whipplei 💊 Prolonged antibiotics (tetracycline or TMP-SMX)

Clinical

Chronic diarrhoea, often steatorrhea in fat malabsorption.
Abdominal bloating, cramping, and excessive gas.
Weight loss despite adequate caloric intake.
Calcium and Vitamin D loss: Osteoporosis, tetany
B12 loss Macrocytic anaemia, glossitis, neuropathy.
Iron loss: Microcytic anaemia, fatigue.

🔎 Investigations

Microcytic anaemia - Iron deficiency and Macrocytic anaemia - Folate and Iron deficient. Dimorphic is both
Low albumin, low calcium and phosphate, macrocytic hypochromic anaemia, Low ferritin (iron deficiency)
Low folate and B12 due to malabsorption
Low calcium and raised alkaline phosphatase (Vitamin D and Calcium malabsorption)
Prolonged PT due to Vitamin K deficiency
Stool Analysis: Qualitative faecal fat (Sudan stain), quantitative faecal fat (72-hour collection), stool elastase (for pancreatic insufficiency), stool pH, and reducing substances.
Blood Tests: FBC, serum electrolytes, albumin, prealbumin, iron studies, vitamin levels (B12, D, E), prothrombin time (PT), and thyroid function tests.
Serologic Tests: Tissue transglutaminase (tTG) antibodies for coeliac disease, antigliadin antibodies, anti-Saccharomyces cerevisiae antibodies (ASCA) for Crohn’s disease.
Breath Tests: Lactose intolerance (hydrogen breath test), SIBO (glucose or lactulose breath test).

Imaging

Upper Endoscopy with Biopsy: mucosal causes such as coeliac disease, Whipple’s disease, and tropical sprue.
Small Bowel Follow-Through or MR Enterography: Useful for structural abnormalities, strictures, or Crohn’s disease.
CT or MRI: pancreatic pathology, lymphatic abnormalities, and abdominal masses.

Specific Management

Coeliac Disease: Lifelong gluten-free diet.
Crohn’s Disease: Immunosuppressants, biologics, and possibly surgery.
Pancreatic Insufficiency: Pancreatic enzyme replacement therapy (PERT).
SIBO: Antibiotics (e.g., rifaximin), prokinetics.
Lactose Intolerance: Lactose-free diet or enzyme replacement.

General Management

Dietary Modification: Tailored to specific deficiencies; low-fat diet in fat malabsorption, lactose-free diet, gluten-free diet.
Supplementation: Oral or parenteral vitamins and minerals based on specific deficiencies (e.g., B12, iron, calcium, fat-soluble vitamins).
Caloric Support: In severe cases, enteral nutrition (e.g., elemental diets) or parenteral nutrition may be necessary.

The content on this website is provided for educational and informational purposes only to support exam preparation (e.g., MLA, MRCP, USMLE) and learning. This is NOT medical advice, diagnosis, treatment, or professional guidance. It does not replace consultation with a qualified healthcare professional, official guidelines (e.g., NICE, GMC, BNF), or supervised clinical practice. Always verify information with current, authoritative sources. Makindo and its contributors accept no liability for any reliance on this content, including errors, omissions, or any resulting harm, loss, or consequences. By using this site, you agree to these terms.

Malabsorption - small intestine

Causes

Clinical

🔎 Investigations

Imaging

Specific Management

General Management

Categories