A genetic predisposition to inflammatory bowel disease has long been suspected,given that there are ethnic and familial aggregations of these disorders [1,2]. In the 1990s, several genetic epidemiological studies have enabled the risk ofrecurrence in families to be better defined.
Immunopathogenesis of Inflammatory Bowel Disease: Role of Cytokines and Immune Cell-Enterocyte Interactions
For over half a century, and despite progressively intensified research efforts,the etiology of inflammatory bowel disease remains an enigma. The most widelyaccepted comprehensive theory suggests that the pathogenesis of Crohn’s diseaseand ulcerative colitis is multifactorial, resulting from a complex interplay ofgenetic predisposition, environmental and immunological factors .
Man and animals are protected from a wide range of microorganisms (parasites,bacteria, moulds, yeasts, fungi, and viruses) by a highly complex biologicalresponse which is executed by the immune system .
Clinical and Pathological Aspects of Inflammatory Bowel Disease
The term “inflammatory bowel disease” applies to bowel diseases of unknownetiology characterized by chronic and often relapsing inflammation. They includeulcerative colitis, Crohn’s disease, indeterminate colitis, pouchitis, and microscopiccolitides.
Diagnostic Criteria for Inflammatory Bowel Disease in Adults
Inflammatory bowel disease comprises disorders of unknown etiology. Thediagnosis is made on the association of symptoms and signs and sometimes on thefamily history of the subject, since there is at present no specific clinical, morphological,or biological diagnostic test.
Diagnostic Criteria for Chronic Inflammatory Bowel Disease in Childhood
Until the 1970s, Crohn’s disease was considered to be uncommon in children,although ulcerative colitis had been recognized in children since the 1920s .The diagnosis of Crohn’s disease is more difficult in children because systemicmanifestation such as growth failure and delayed puberty  may dominate theearly clinical picture.
The genetic basis of diseases is becoming more widely understood. It has longbeen known that certain diseases are inherited through genetic defects. However,other disorders are manifested by alterations in the expression genes central todisease processes.
Inflammatory bowel diseases, in particular Crohn’s disease, have profoundeffects on nutritional status  and malnutrition is common, even in patients withrelatively quiescent disease attending an outpatient clinic (Table 1). In a recentprospective survey of 154 consecutive patients referred to the gastrointestinalclinic of a teaching hospital, 11 of 47 (23%) with Crohn’s disease had significantprotein-energy malnutrition.
Use of Macro- And Micronutrients for Nutrition Support in Inflammatory Bowel Disease
The appropriate use of nutritional treatment in the management of inflammatorybowel disease has been an unresolved issue. There is no disagreement thatreplacement therapy is indicated when nutrient deficiency is present.
The relative merits of treating Crohn’s disease with corticosteroids or enteralnutrition remains an area of controversy, particularly following meta-analyseswhich implied that corticosteroids were more effective at inducing clinical remission[1, 2].
The inflammatory bowel diseases are chronic inflammatory processes thatmay have pathological and clinical manifestation in any part of the alimentarytract from the mouth to the anus, but mainly in the ileum and the colon.
Potential Role of Glutamine Administration in Inflammatory Bowel Disease
The molecular mechanisms of intestinal injury in Crohn’s disease and ulcerativecolitis are increasingly being elucidated. These findings have led to newanticytokine treatments designed to decrease mucosal damage in inflammatorybowel disease.
Monoclonal Antibody Therapy in Inflammatory Bowel Disease
During the last decade, major advances have been made in therapeuticapproaches to both Crohn’s disease and ulcerative colitis. Nevertheless, manypatients continue to pose a therapeutic challenge because they remain symptomaticdespite standard medical intervention.