For children with severe cases of Crohn’s disease , corticosteroids and disease modifying drugs are often used, since it is an inflammatory auto-immune disease.
An other possible approach is enteral feeding through a feeding tube, technically called Exclusive Enteral Nutrition (EEN). The treatment has been found to be as efficacious as corticosteroids .
However, there are many other treatments options such as aminosalicylates ; immuno-suppressive and biologic drugs, as described in a New York Times article . Note the absence of EEN in the NYT list. EEN needs to be compared to those, too.
The children were fed a formula which may contain whole proteins (polymeric) or modified proteins (e.g. elemental).
The success rate has been rather good:
“…Twelve of 15 (80%) newly diagnosed CD and seven of 12 (58%) with long-standing disease entered remission…”
Two issues :
- The child has to be fed through a feeding tube for 8 weeks 
- Besides the discomfort, the methods has some risks, namely , pneumonia and aspiration 
Exactly why the treatment works is not fully understood, quoting , the possible mechanisms are:
- reduced gut activity due to the administration of a solely liquid diet,
- indirect nutritional effects,
- direct anti-inflammatory effects,
- via modulation of the gastrointestinal microflora.
- Journal of Gastroenterology and Hepatology. ; “Exclusive enteral feeding as primary therapy for Crohn’s disease in Australian children and adolescents: a feasible and effective approach.” ;2006
- New York Times ;
- Digestive Diseases and Sciences. ; “Longer-Term Outcomes of Nutritional Management of Crohn’s Disease in Children.” ; 2012
- INFLAMMATORY BOWEL DISEASE: A PRACTICAL APPROACH, SERIES #51; Seymour Katz, M.D., Series Editor;PRACTICAL GASTROENTEROLOGY • APRIL 2009
- Practical Gastroenterology,” Aspiration Risk and Enteral Feeding: A Clinical Approach” ; 2003