E nteral nutrition is an effective therapy for active Crohn’s disease (CD) although less effective than steroids. This has been shown in a number of original studies and metaanalyses. 2 Enteral nutrition leads to remission in approximately 60% of patients within 4–6 weeks. Unfortunately, enteral nutrition has never been compared with placebo or other medical therapies such as mesalamine or topical steroids. With the lack of such studies demonstrating that enteral nutrition is superior to placebo, the question has been raised if enteral nutrition has any therapeutic effect at all. However, remission rates with enteral nutrition range from 53% to 80%, which is higher than remission rates of placebo groups in most studies, which range from 18% to 40%. Therefore, a direct anti-inflammatory effect of enteral nutrition in active CD is generally accepted. The therapeutic efficacy of enteral nutrition in active CD is also suggested by results of recent studies demonstrating mucosal healing as well as a reduction in proinflammatory cytokines 4 by enteral nutrition. The effect of enteral nutrition appears to be similar if the diet is drunk or applied via a tube and is also comparable with the effect of parenteral nutrition. Specific compositions of enteral diets—elemental diets or diets containing specific components— have no advantage over standard polymeric diets. 5–7 In adults, enteral nutrition is rarely used as the sole therapy for active CD in clinical practice. This is partly due to its inferiority compared with steroids and partly to the inconvenience of enteral nutrition, resulting in low patient compliance—specifically if the mostly unpalatable diets are drunk. This appears to be different in children, who accept enteral nutrition much better, with compliance rates of up to 100%. Furthermore, malnutrition with growth retardation is a leading symptom in adolescents suffering from CD, and enteral nutrition does effectively improve the nutritional status of CD patients and increase growth velocity. 9 Therefore, enteral nutrition is considered the treatment of choice for active CD in children, as also reflected by recent guidelines. The mode of action of enteral nutrition is still unclear although several mechanisms have been discussed: (a) bowel rest with alteration of the intestinal flora and elimination or reduction of dietary antigens and (b) improvement in nutritional status by increase in nutritional intake and/or increase in substrate absorption as well as reduction in intestinal protein loss. A study by Johnson and colleagues in this issue of Gut raises new questions about both the efficacy and possible mechanism of action of enteral nutrition in active CD (see page 356). They randomised children with active CD to either receive 100% of their nutrition as elemental diet (total enteral nutrition) or only 50% (partial enteral nutrition), thereby replacing 50% of standard food by an elemental diet. Total nutritional intake was similar in both groups. They found a remission rate of 42% with total enteral nutrition and a significantly lower rate of 15% with partial enteral nutrition. However, this low remission rate, especially in the partial enteral nutrition group, does not exceed the range reported in placebo groups, arguing against a significant role for enteral nutrition in the treatment of CD. Two specific questions need to be discussed to explain these results and put them into perspective.