Malabsorption in Children - Clinical Evaluation and Management

(10-Mark Answer - MD Paediatrics Exam)

DEFINITION

AETIOLOGY / CLASSIFICATION

By Pathophysiological Phase:

Common Causes in Children by Age:

• Neonates/Infants: Congenital lactase deficiency, glucose-galactose malabsorption, microvillus inclusion disease, tufting enteropathy, abetalipoproteinaemia
• Toddlers/Preschool: Coeliac disease, post-enteritis syndrome, Giardia lamblia, cow's milk/food protein enteropathy, cystic fibrosis
• School-age/Adolescents: Coeliac disease, inflammatory bowel disease (Crohn's disease), SIBO, bile acid malabsorption

CLINICAL EVALUATION

A. History

• Gastrointestinal: Chronic or recurrent diarrhoea, pale/bulky/foul-smelling/greasy stools (steatorrhoea), abdominal distension, flatulence, vomiting
• Growth: Failure to thrive, weight loss or poor weight gain, short stature, pubertal delay
• Nutritional deficiency symptoms: fatigue, easy bruisability (vit K), night blindness (vit A), bone pain (vit D), tetany (Ca/Mg), glossitis/angular stomatitis (B-complex/iron), oedema (protein loss)
• Dietary history: breastfeeding, formula type, introduction of gluten, food restrictions
• Family history: coeliac disease, cystic fibrosis, IBD
• Travel history: parasitic infections (Giardia, Cryptosporidium)
• Drug history: broad-spectrum antibiotics (SIBO), methotrexate (folate)
• Past history: recurrent chest infections (CF), previous gut surgery (short bowel), neonatal liver disease

B. Physical Examination

INVESTIGATIONS

First-Line (Screening):

1. Complete blood count: microcytic anaemia (iron), macrocytic (folate/B12), eosinophilia (allergy/parasites)
2. Serum ferritin, iron, TIBC
3. Serum folate, vitamin B12
4. Serum albumin, total protein (protein malabsorption)
5. Serum calcium, phosphate, alkaline phosphatase (vitamin D deficiency)
6. Serum 25-OH vitamin D
7. Prothrombin time/INR (vitamin K)
8. Stool examination: microscopy for ova/parasites, Giardia antigen, reducing substances (carbohydrate malabsorption), Sudan III stain for fat globules, stool pH (<5.5 in carbohydrate malabsorption)
9. Tissue transglutaminase IgA (tTG-IgA) + total serum IgA - screening for coeliac disease
10. Sweat chloride test (if CF suspected)
11. Abdominal ultrasound (selected patients)

Second-Line (Disease-specific):

1. Faecal elastase-1: Screening for exocrine pancreatic insufficiency (EPI) - recommended in all children with fat malabsorption (European Consensus on Malabsorption, UEG 2025); <100 μg/g = severe EPI
2. Faecal calprotectin: elevated in IBD (>200 μg/g suggestive)
3. Quantitative faecal fat (72-hr collection): gold standard for steatorrhoea; >7 g/day on 100 g/day fat intake is abnormal; in diarrhoea >14 g/day used as cutoff (Sleisenger & Fordtran)
4. Hydrogen breath test: lactose breath test (lactose malabsorption), glucose/lactulose breath test (SIBO)
5. Upper GI endoscopy + duodenal biopsy: essential for coeliac disease (Marsh grading), microvillus inclusion disease, autoimmune enteropathy
6. Colonoscopy + biopsy: IBD evaluation
7. Small bowel imaging: MR enterography (Crohn's), barium meal follow-through
8. Genetics/metabolic: CFTR mutation analysis, immunoglobulins (hypogammaglobulinaemia), lymphocyte subsets (IPEX)
9. Video capsule endoscopy: refractory coeliac, subtle small bowel disease missed by standard endoscopy (Sleisenger)

Diagnostic Algorithm (UEG/ESPGHAN 2025):

MANAGEMENT

1. General Principles

• Nutritional rehabilitation is the cornerstone alongside treating the underlying cause
• Multidisciplinary approach: paediatrician, paediatric gastroenterologist, dietitian, clinical geneticist
• Monitor fat-soluble vitamins (A, D, E, K) and micronutrients regularly in all malabsorptive states

2. Nutritional Management

3. Condition-Specific Management

• Strict, lifelong gluten-free diet (GFD) - removal of wheat, barley, rye
• Nutritional supplementation on GFD initiation (iron, folate, B12, vitamins)
• Repeat tTG-IgA at 6-12 months to assess compliance
• (European Society for Coeliac Disease 2025 updated guidelines, PMID 40999951)

• Pancreatic enzyme replacement therapy (PERT): lipase 500-4000 IU/kg/meal, titrated to steatorrhoea
• Fat-soluble vitamin supplementation (ADE+K as water-miscible preparations)
• High-calorie, high-fat diet (50% fat) - do NOT restrict dietary fat
• Salt supplementation in CF

• Metronidazole 15 mg/kg/day × 7-10 days (or tinidazole single dose)

• Dietary lactose reduction (not complete elimination)
• Lactase enzyme supplementation with meals
• Calcium and vitamin D supplementation
• (UpToDate: Lactose intolerance and malabsorption, last updated Oct 2024)

• Extensively hydrolysed formula (eHF) as first-line
• Amino acid formula (AAF) if eHF not tolerated
• Maternal dairy exclusion if breastfeeding

• Exclusive enteral nutrition (EEN) as first-line induction in paediatric Crohn's: 6-8 weeks polymeric/semi-elemental formula
• Maintenance: azathioprine, biologics (anti-TNF); nutritional support ongoing

• Parenteral nutrition (PN) initially
• Gradual enteral feeding advancement to stimulate intestinal adaptation
• Teduglutide (GLP-2 analogue) approved as intestinal growth factor
• Citrulline levels as biomarker of functional enterocyte mass

• Rifaximin or metronidazole/co-amoxiclav courses
• Address underlying predisposing condition

• Very low-fat diet (<15 g/day)
• High-dose vitamin E (100-200 mg/kg/day) to prevent neurological complications
• Fat-soluble vitamin supplementation

4. Monitoring

• Growth parameters every 3-6 months
• Repeat nutritional labs (iron, vitamins, albumin) at 3-6 month intervals
• Bone mineral density (DEXA) in prolonged malabsorption (coeliac, CF, IBD)
• Developmental milestones and neurodevelopment (at risk with B12, vitamin E deficiency)

COMPLICATIONS OF UNTREATED MALABSORPTION

• Stunting, permanent growth failure
• Pubertal delay
• Osteoporosis / pathological fractures
• Peripheral neuropathy, subacute combined degeneration (B12)
• Night blindness, corneal ulceration (vitamin A)
• Coagulopathy (vitamin K)
• Immune deficiency (zinc, protein)
• Neurological regression in abetalipoproteinaemia (if vitamin E not replaced)

RECENT UPDATES (2024-2025)

1. European Consensus on Malabsorption (UEG & SIGE, 2025): First pan-European consensus recommending a stepwise algorithmic approach; faecal elastase as the first test for fat malabsorption in children; structured first-line vs second-line testing framework. (United European Gastroenterol J, 2025)
2. ESPGHAN 2025 Coeliac Guidelines (PMID 40999951): Updated guidance on no-biopsy diagnosis in children (if tTG-IgA >10x ULN + positive EMA + HLA-DQ2/8 positive) and emphasis on nutritional monitoring post-GFD.
3. Comprehensive Paediatric Malabsorption Review (Pucinischi et al., Nutrition 2025, PMID 40769093): Emphasises three-phase diagnostic approach (luminal, mucosal, transport), unique challenges in neonates (developmental immaturity), and multidisciplinary management framework.
4. GLP-2 analogues (Teduglutide): Now endorsed in paediatric short bowel syndrome for intestinal adaptation, reducing PN dependence.
5. SIBO recognition: Increasing recognition as a contributor to functional-seeming malabsorptive symptoms in children, particularly those with motility disorders or prior gut surgery.

ANSWER STRUCTURE SUMMARY (for 10-marker writing under exam conditions)

• Sleisenger and Fordtran's Gastrointestinal and Liver Disease (10th ed) - Tables 104.3, 104.8, diagnostic algorithm
• The Harriet Lane Handbook, 23rd ed - Vitamin supplementation in malabsorption
• Pucinischi V et al. "Enhancing pediatric practice: A comprehensive review on malabsorption in pediatrics for diagnostic and management approach." Nutrition 2025;140:112895. [PMID: 40769093]
• European Consensus on Malabsorption, United European Gastroenterology Journal 2025 (UEG & SIGE, ESPGHAN)
• European Society for Coeliac Disease 2025 Updated Guidelines [PMID: 40999951]
• UpToDate: "Lactose intolerance and malabsorption: Clinical manifestations, diagnosis, and management" (updated Oct 2024); "Poor weight gain in children older than two years" (updated Jul 2025)

Note on Nelson's Textbook of Paediatrics and Piyush Gupta's Paediatrics: These key references are not in the available digital library for this session. The content above integrates equivalent gold-standard paediatric GI sources (Sleisenger & Fordtran, Harriet Lane, and 2025 updates). When writing your exam answer, supplement with the following Nelson's content you would know: Chapter on "Malabsorptive Disorders" covers the D-xylose absorption test (low in mucosal disease, normal in pancreatic insufficiency), 72-hr faecal fat, sweat test, and the diagnostic approach table. Piyush Gupta emphasises Indian-context causes: giardiasis, tropical sprue, post-infectious enteropathy, persistent diarrhoea, and nutritional rehabilitation with F-75/F-100 WHO formulas.