Abstract: Ulcerative colitis and Crohn disease,  which fall into the category of inflammatory bowel disease(IBD), are both chronic inflammatory diseases characterized by unclear etiology and repeated recurrence. These characteristics have caused most  of  the patients suffering from decades of trouble, and malnutrition frequentlyoccurs during theprogress of the disease,  even atthe remission period. Malnutrition includes protein energy deficiency, overweight, vitamin, mineral and trace elements deficiency. There are numerous factors associated with malnutrition in patients with IBD, such as poor intestinal absorption, loss of nutrients caused by intestinal ulcers and inflammation, excessive growth of small intestinal bacteria, use of glucocorticoids, and dietary restrictions. Nutritional support is essential for IBD patients, especially for the maintenance of normal growth and development of IBD patients in their childhood, for the treatment of CD patients at active stage, and for the reduction of perioperative complications in patients with IBD.

Key words: inflammatory bowel disease, malnutrition, nutritional and metabolic disease