Exclusive Enteral Nutrition

In addition to inducing remission in Crohn’s disease, there is a potential for EEN to improve outcomes in the following settings. Although further studies are needed to thoroughly evaluate its use in some of these settings, there is little downside to using EEN with potentially significant benefits. Thus, patients and healthcare providers are encouraged to consider this option in shared decision-making.‍

• When Fistulas, Abscesses, or Strictures are Present
  Adjunctive use of EEN may be especially beneficial in this setting to promote tissue healing, fistulae closure, and to reduce the need for surgery.^{1, 2, 3, 4}
• Before/After Surgery or During Hospitalization
  EEN and Partial enteral nutrition (PEN) improve the outcomes of surgery and should be considered as adjunctive therapy in all pre-surgical patients.^{5, 6, 7}‍
  

1. Children vs Adults: Exclusive enteral nutrition is a well-established method of inducing remission in children with Crohn's disease. Initial studies have shown that EEN may be less effective in adults, but this may be due to poor compliance. More recent studies have shown EEN to be effective in adults to induce remission and transmural healing¹ as well as efficacy in complicated disease with fistulas, abscesses, and strictures ^2,3,4 and in adults refractory to medications⁵ and is a recommended treatment option in adults with Crohn’s disease by some consensus groups.⁴‍
2. Crohn’s Disease vs Ulcerative Colitis: Exclusive enteral nutrition has been shown to be very effective in children with Crohn’s disease with emerging data in adults with Crohn’s disease, but it has not been well studied in patients with ulcerative colitis and is therefore not a customary treatment for ulcerative colitis. However, some papers suggest that it may have a similar benefit in ulcerative colitis⁶. When used adjunctively in hospitalized patients with severe UC, a reduced length of stay, improvement in inflammatory markers, and reduced rates of colectomy or rehospitalization were noted.⁷ ESPEN recommends the adjunctive use of EEN in severe UC.⁸‍
3. Special Consideration for the Crohn’s Disease Exclusion Diet (CDED): A full 6-to-8-week course of EEN may not be necessary if adopting the CDED. Instead, a short course of EEN (2 weeks) or partial enteral nutrition (PEN) combined with CDED in the Induction Phase is part of the treatment plan and replaces the standard course of EEN. This method has been shown to be effective in inducing remission in children with Crohn’s disease⁹, as well as in adults.¹⁰ The data for the CDED are not as extensive as that for EEN for induction of remission but are very promising for this emerging whole-foods-based dietary approach.‍
4. Processed Ingredients: Some patients with IBD prefer to avoid processed foods, such as the over-the-counter formulas used for EEN. It is important to understand that despite the processed nature of these formulas, EEN is very effective. When the alternative is active disease or steroids, often the processed ingredients are the lesser concern. Patients that choose to try EEN, should work with their healthcare providers to find the formula that is right for them.
5. ‍Compliance Difficulty: Exclusive enteral nutrition duration is generally 6 to 8 weeks, and can last as long as 12 weeks. It can be difficult to give up solid foods for such a long period of time. Some find EEN easier than eating solid foods when they are very symptomatic, but others may find it difficult. Caregivers, family, friends, and the healthcare team are essential to supporting patients through the treatment period.
6. ‍Using EEN as an Alternative to Steroids: Steroids are often used to induce remission instead of EEN. Although many tolerate the steroids short term, EEN may serve as a potentially better alternative to induce remission.
   

Some of the underutilization of EEN in the US may be explained by the fact that there has not been an established transition from EEN to a dietary maintenance therapy. Although there is not yet an established single dietary recommendation, following EEN with a therapeutic diet may improve chances of maintaining remission, compared with PEN or a return to a liberalized diet, as a return to a liberalized diet results in rapid increases in inflammatory markers¹and high rates of relapse.² Partial enteral nutrition (PEN) as sole therapy following EEN is ineffective long term but has been shown to help maintain remission when combined with medications.³

Some patients choose to begin nutritional therapy with a course of exclusive enteral nutrition (EEN) in order to improve health, weight, nutrition, and/or tolerance of foods before changing their dietary habits. Using EEN as a bridge to other nutritional therapy options can make the journey easier. A wider range of foods may be tolerated from the start, and determining which foods are tolerated may be easier. However, this option is not right for everyone. See Factors to Consider (above) for a list of considerations to determine the best path.

Traditionally, transitioning off EEN is done gradually by slowly adding more solid foods into the diet. However, as commercial formulas for EEN are not compliant with many of the therapeutic diets, questions often arise as to how to best transition. There is no established protocol for this situation. The experts at Seattle Children Hospitals have provided some insight regarding where to begin regarding phases/stages and whether to transition slowly or quickly:

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Following Stages or Phases: According to the Nimbal website, at Seattle Children’s Hospital, if remission is achieved on EEN, it is recommended to transition to the full array of foods allowed on the therapeutic diet (in their case SCD). If still symptomatic after EEN, then they are more likely to use a staged approach to adding foods back in, with less risky foods introduced first.

Length of Transition Period: There is no defined protocol for the length of transition and research is needed to provide guidance. In this video presentation by Dale Lee, MD, MSCE, of Seattle Children’s Hospital, two methods are proposed.
The first is a graded transition that moves more gradually to the therapeutic diet over a period of a few weeks. This approach takes advantage of the fact that the effects of EEN will continue to linger for a while after discontinuing and uses that period to transition cautiously to a therapeutic diet. It is consistent with the traditional approach for transitioning off EEN.

The second approach is a much quicker transition to solid foods. This approach acknowledges the fact that the EEN formula is not compliant with most of the therapeutic diets, and recognizes that the therapeutic diet can’t start working to its full potential until the formula is discontinued.