Investigations

Blood count, renal, liver and bone biochemistry
Inflammatory markers, e.g. ESR, CRP
Immunoglobulins A/G/M/E
Specific IgE levels to food antigens: milk/soya/egg/wheat/nuts/ fish
Coeliac serology:
- IgA tissue transglutaminase
- Endomysial antibody
- HLA-DQ2/DQ8
Stool analysis:
- Bacterial, viral and parasite examinations
- Calprotectin: a neutrophil protein stable in stool. Although specificity is suboptimal, a negative result reassures that inflammatory bowel disease is unlikely
Small bowel imaging (Figure 10.2):
- Magnetic enterography with oral and intravenous contrast
- Barium meal and follow-through (± per-oral pneumocolon)
- Ultrasound scanning: bowel wall thickness, increased vascularity, mass
Investigative dietary trials:
- Lactose-free diet
- Hypoallergenic diet
- Lactose/sucrose/fructose breath tests (poor sensitivity and specificity)
- Endoscopy: oesophago-gastro-duodenoscopy and ileocolonoscopy with biopsies (Figure 10.3)

Figure 10.2 (A) Barium radiology showing bowel loop separation and ‘rose-thorn’ ulceration of the terminal ileum and right colon in Crohn’s disease. (B) Magnetic resonance enterography provides imaging of the lumen, mucosa and bowel wall. A thick-walled narrow diseased segment in the right iliac fossa, with an area of pseudosacculation abutting the bladder (high signal from contrast in the lumen) and bowel loop separation with fat-wrapping (low signal).

Figure 10.3 Endoscopic appearances of lesions in inflammatory bowel disease. (A,B) Crohn’s disease deep linear ‘snail-track’ ulcers (A) or apthous ulcers (B). (C) Ulcerative colitis is typically diffusely red with bleeding and ‘grains of salt’ granularity.

Red flags: Pitfalls in the diagnosis of diarrhoea

Spurious diarrhoea in functional constipation with incomplete rectal emptying
Anaemia, raised inflammatory markers and/or low serum albumin suggest inflammatory bowel disease
Malnutrition is common in Crohn’s disease, including deficiency of iron, vitamin B₁₂, vitamin D and zinc

Management

Crohn’s disease (see Algorithm 10.1)

Inducing remission

Exclusive enteral nutrition, for 6–8 weeks to induce remission:
- Patient acceptance limits its use
- Polymeric feeds are more palatable then elemental formulae
- Nasogastric tube feeding can be a solution in some cases
Systemic corticosteroids:
- Administered parentally in severe disease, e.g. IV methyprednisolone 1–2 mg/kg (max 60 mg) per day or hydrocortisone 2 mg/kg (max 100 mg) qid
- Supplemental nutrition is often required by NG tube
- Specific nutrient deficiencies are common, e.g. iron, vitamin D, zinc

Algorithm 10.1 Management of Crohn’s disease

Disease relapse

Exclusive enteral nutrition for 6–8 weeks and oral corticosteroids are both effective in 60–80% of cases
Active perianal disease: metronidazole 7.5 mg/kg/dose tds and/or ciprofloxacin 5 mg/kg/dose bd

Information: Exclusive enteral nutrition liquid diet therapy

Polymeric (whole protein) or elemental (amino acid) liquid diet formula with remission is usually attained within 1–2 weeks, is effective for luminal, oral and perianal disease
Efficacy can be affected patient and parent choice, compliance, palatability
Has added benefits of avoiding corticosteroid toxicity and improved nutritional status
Most children need approximately 120% of estimated average energy requirement for age. This however needs to be adjusted according to individual needs and dietetic support is essential
Food re-introduction over 1–3 weeks, dependent on patient symptoms