Importance of nutrition in inflammatory bowel disease

Table 1 Causes of malnutrition in IBD (modified from García-Manzanares et al[63])

Decrease in oral intake	Restrictive diets, therapeutic fasting
	By the disease itself: diarrhea, abdominal pain, nausea and vomiting, etc
	Alteration in taste: due to drugs, vitamin and mineral deficiencies, pro-inflammatory mediators
	Anorexigenous effect of pro-inflammatory cytokines
Gastrointestinal losses	Diarrhea
	Rectorrhagia/hematochezia
	Loss of mucus and electrolytes
	Protein-losing enteropathy
Metabolic disorders	Increase in resting energy expenditure
	Enhanced fat oxidation
Increase in nutritional requirements	Inflammatory states
	Increased basal oxidative metabolism
	Infectious complications
	Post-surgery
Drug interaction	Corticoids and calcium reabsorption
	Corticoids and protein catabolism
	Salazopirine and folates
	Methotrexate and folates
	Cholestyramine and liposoluble vitamins
	Antimicrobials and vitamin K
	Anti-secretors and iron
Poor absorption of nutrients	Reduction of the absorptive surface: intestinal resection, enteric fistulas, hypertrophy of the villi
	Blind loops, bacterial overgrowth
	Poor absorption of bile salts in ileitis or resection