Inflammatory Bowel Disease

Pathogenesis

Variations

Affects any region of intestine through discontinuous pattern

Crohn's Disease

Only affects colon and rectum in continuous retrograde pattern

Ulcerative Colitis

Dx difficult - uses montreal categories

A1 catetory for dx age <16 years, A2/3 dx age 17;40 years. General affect population experience ulceration in terminal ilium and colon.

Transmural inflammation (full thickness)

Only affects mucosal/sub-mucosal layers

Formation of strictures (narrowing of bowel wall) or fistulas (tracts between the bowel and other organs).

Genetics factors: autophagy, bacteria handling, chemokines/cytokines

Symptoms and complications

abdominal cramps, diarrhoea, constipation, urgency, fever, loss of appetite, fatigue, weight loss, anaemia

Environmental factors:

Complications - abscess (pus) as inflammation extends through bowel wall.
Fistulas - disease tracts outside of bowel via abscess extending through wall forming cavity
Stricture - narrowing of bowel due to inflammation/scarring causing possible blockage
Toxic Megacolon - severe ulceration causing large bowel to severely extent
Perforation - hole/break in wall (need urgent surgery)

Extraintestinal manifestations - joint pain, skin conditions, eye inflammation, liver disorders, osteoporosis, asthma, coeliac, rheumatoid arthritis, multiple sclerosis, increased risk of cancers

Micronutrient deficiencies - iron, vitamin D, vitamin B12, zinc, folate, calcium, magnesium

Medical mx

Respectful paradigm
Steroids... overtime suppress immune system increasing risk of infection, skin disorders, affect appetite, osteoporosis
Immunomodulators... for steroid dependent pt, inhibit Tcell function to stop inflammatory response
Biologics... anti TNFa via IV, although higher risk of infection
Surgery - for obstruction, fistula or refractory disease

Dietetic management

Malnutrition in CD reported in 20-85% - anorexia, malabsorption, increased intestinal losses, systemic inflammation

Nutritional Goals

  1. Improve/maintain nutritional status.
  1. Aim for symptom control
  1. Identify and address malabsorption. Manage deficiencies: B12, bile salts, fat soluble vitamins, iron
  1. Tackle nutrition knowledge. FAD diets/ food avoidances
  1. Look for disordered eating
  1. Consider supplementation if required - ONS, EEN

If weight stable …EER 100 – 125kJ/kg/day. EPR 1.2 – 1.5g/kg/day (with active inflammation).

If malnourished …EER 125 – 145kJ/kg/day (for repletion) EPR 1.2 – 1.5g/kg/day

General management

Food fortifiaction if required

Focus on good quality, high nutrient, low processed foods

Don't restrict fibre unless risk of obstruction

Flare - up management

HPHE to address unintended weight loss/poor appetite

Low fibre for stricturing and obstructions

Hydration - consider isotonic drinks for electrolytes

Liquid diet or EEN - consideration for steroid dependent pt, SB disease, stricturing, fistulating or pre-existing malnutrition

GESA inflammation treatment

Aminosalicylates, corticosteroids, immunomodulators, biologics, antibiotics, exclusive enteral nutrition (EEN)

EEN

Liquid polymeric diet (oral or enteral) for 6-8 weeks followed by food re-introduction phase

Negatives: palatability, lack of variety, lack of expertise

Positives: disease control efficacy, clinical remission, mucosal healing, anti-inflammatory properties, manage nutrient deficiencies, reduce anaemia, promote bone turnover, promote microbiome

Food reintroduction: gradual 5-10 days, food intolerances may present (possible relapse)

Monitor pt with active disease 1x/week. After initial 2 weeks of EEN therapy if pt is not improving consider alternate pathway.

Montreal B (behaviour) as structuring or penetrating
B1 without stricturing or penetration
B2 stricture (narrowing in intestine)
B3 penetrating (tract/fistula appears between two structures)
B4 Perianally penetratin

Montreal L category L1 terminal ileum L2 colon L3 ileocolon L4 upper GI tract (stomach oesophagus)

Proctitis: only affects rectum 30-60% patients. Symptoms - rectal bleeding, tenesmus, urgency

Left-sided colitis: 16-45% patients. Symptoms - proctitis, diarrhoea, abdominal cramping

Extensive colitis: 15-35% patients. Symptoms - left sided colitis, constitutional symptoms, fatigue, fever