Exclusive Enteral Nutrition

Exclusive Enteral nutrition involves the use of a nutritionally complete liquid diet which is often an over-the-counter meal replacement formula that provides all daily calories. Thus, no solid food is taken for the duration of the treatment, usually 6- 8 weeks, up to 12 weeks, or longer, depending upon progress and goals.

6 different flavour liquid drinks with straws
Liquid nutrition  of different flavours in glasses

Introduction

Exclusive Enteral Nutrition (EEN) involves the exclusive use of a liquid diet with no solid food for 6-8 weeks, sometimes up to 12 weeks. It is a well-established therapy to induce remission of pediatric Crohn’s disease, with increasing evidence for use in adults and some emerging data as an adjunctive therapy in severe ulcerative colitis.

EEN can also be used during a flare, before or after surgery, as part of treatment for fistulas, abscesses, or strictures, or as a bridge to a new therapy (while waiting for the start or the onset of a new treatment).
EEN can be administered orally with over-the-counter meal-replacement formulas. For those who find it difficult to drink the necessary daily amount of formula, a nasogastric tube may be used to initiate the therapy or more easily meet daily nutrient requirements.

It is important to work with your medical team and dietitian when using EEN to be sure that all caloric and nutritional needs are met. Regular check-ups during the treatment process provide much-needed support for patients and families to be successful.

EEN is the Foundation of Nutritional Therapy

Exclusive enteral nutrition is so effective at inducing remission in pediatric Crohn’s disease that it is recommended as the first line of treatment in Europe,1-2 Canada,3 Japan,4-5 Australia,6 and the U.S.7 but is underutilized in the U.S. compared to other countries.8 Given the very high rate of remission (80%) with minimal side effects, it is a particularly attractive choice for children. 9 Additional benefits include resolving nutritional deficiencies, improving growth and weight gain, improving bone health, and inducing mucosal healing.10 EEN is an effective and underutilized nutritional option for both children and adults. See Factors to Consider.

EEN is the foundation of nutritional therapy upon which whole-foods-based approaches are built. If EEN can provide these benefits with a liquid diet, is it possible to induce remission or to maintain it with a whole-foods-based diet? Part of the answer may lie in the proposed mechanisms for the efficacy of EEN, which include the exclusion of potentially harmful ingredients, giving the bowel rest, providing essential micronutrients that are easily absorbed, and modulating the microbiome, which are similar components of IBD therapeutic diets.

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EEN in Complicated disease and Peri-operatively

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

Factors to Consider

  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.

Transistioning from EEN to a Therapeutic Diet

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:

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.

References. 

EEN in the Foundation of Nutritional Therapy
  1. Ruemmele FM, Veres G, Kolho KL, et al. Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn's disease. J Crohns Colitis. 2014;8(10):1179-1207. 10.1016/j.crohns.2014.04.005
  2. van Rheenen PF, Aloi M, Assa A, et al. The Medical Management of Paediatric Crohn's Disease: an ECCO-ESPGHAN Guideline Update [published online ahead of print, 2020 Oct 7]. J Crohns Colitis. 2020;jjaa161. doi:10.1093/ecco-jcc/jjaa161
  3. Mack DR, Benchimol EI, Critch J, et al. Canadian Association of Gastroenterology Clinical Practice Guideline for the Medical Management of Pediatric Luminal Crohn's Disease. Gastroenterology. 2019;157(2):320-348. doi:10.1053/j.gastro.2019.03.022
  4. Ishige T, Tomomasa T, Tajiri H, Yoden A; Japanese Study Group for Pediatric Crohn's Disease. Japanese physicians' attitudes towards enteral nutrition treatment for pediatric patients with Crohn's disease: a questionnaire survey. doi:10.5217/ir.2017.15.3.345
  5. Ueno F, Matsui T, Matsumoto T, et al. Evidence-based clinical practice guidelines for Crohn's disease, integrated with formal consensus of experts in Japan. J Gastroenterol. 2013;48(1):31-72. doi.org/10.1007/s00535-012-0673-1
  6. Ho SSC, Day AS. Exclusive enteral nutrition in children with inflammatory bowel disease: Physician perspectives and practice. JGH Open. 2018;3(2):148-153. Published 2018 Dec 12. doi:10.1002/jgh3.12121
  7. Critch J, Day AS, Otley A, et al. Use of enteral nutrition for the control of intestinal inflammation in pediatric Crohn disease [published correction appears in J Pediatr Gastroenterol Nutr. 2012 Apr;54(4):573]. J Pediatr Gastroenterol Nutr. 2012;54(2):298-305. doi:10.1097/MPG.0b013e318235b397
  8. Shaikhkhalil AK, Boyle B, Smith J, et al. Using Quality Improvement to Increase Utilization of Enteral Therapy in Pediatric Crohn Disease: Results and Outcomes. J Pediatr Gastroenterol Nutr. 2018;66(6):909-914. doi:10.1097/MPG.0000000000001879
  9. Miller T, Suskind DL. Exclusive enteral nutrition in pediatric inflammatory bowel disease. Curr Opin Pediatr. 2018;30(5):671-676. doi:10.1097/MOP.000000000000066
  10. Day AS, Lopez RN. Exclusive enteral nutrition in children with Crohn's disease. World J Gastroenterol. 2015 Jun 14;21(22):6809-16. doi: 10.3748/wjg.v21.i22.6809. PMID: 26078556; PMCID: PMC4462720.
EEN in Complicated disease and Peri-operatively
  1. Yang Q, Gao X, Chen H, et al. Efficacy of exclusive enteral nutrition in complicated Crohn's disease. Scand J Gastroenterol. 2017;52(9):995-1001. doi:10.1080/00365521.2017.1335770
  2. Heerasing N, Thompson B, Hendy P, et al. Exclusive enteral nutrition provides an effective bridge to safer interval elective surgery for adults with Crohn's disease. Aliment Pharmacol Ther. 2017;45(5):660-669. doi:10.1111/apt.13934
  3. Day A, Wood J, Melton S, Bryant RV. Exclusive enteral nutrition: An optimal care pathway for use in adult patients with active Crohn's disease. JGH Open. 2019 Sep 10;4(2):260-266. doi: 10.1002/jgh3.12256. PMID: 32280775; PMCID: PMC7144766.
  4. Adamji M, Day AS. An overview of the role of exclusive enteral nutrition for complicated Crohn's disease. Intest Res. 2019;17(2):171-176. doi:10.5217/ir.2018.00079
  5. Palchaudhuri S, Albenberg L, Lewis JD. Diet Recommendations for Hospitalized Patients With Inflammatory Bowel Disease: Better Options Than Nil Per Os. Crohns Colitis 360. 2020;2(4):otaa059. doi:10.1093/crocol/otaa059
  6. Harris RE, Duncan H, Buchanan E, et al. Prehabilitation: The Impact of Preoperative Exclusive Enteral Nutrition on Paediatric Patients With Crohn Disease. J Pediatr Gastroenterol Nutr. 2020;70(4):503-507. doi:10.1097/MPG.0000000000002595
  7. Yamamoto T, Nakahigashi M, Shimoyama T, Umegae S. Does preoperative enteral nutrition reduce the incidence of surgical complications in patients with Crohn's disease? A case-matched study. Colorectal Dis. 2020;22(5):554-561. doi:10.1111/codi.14922
Factors to Consider
  1. M Chu, A Day, R Mathias, T Direen, L Broad, K Lynch, R Bryant, P499 Exclusive enteral nutrition induces transmural healing in adults with active Crohn’s disease, Journal of Crohn's and Colitis, Volume 17, Issue Supplement_1, February 2023, Pages i628–i629, doi.org/10.1093/ecco-jcc/jjac190.0629
  2. Yang Q, Gao X, Chen H, et al. Efficacy of exclusive enteral nutrition in complicated Crohn's disease. Scand J Gastroenterol. 2017;52(9):995-1001. doi:10.1080/00365521.2017.1335770
  3. Heerasing N, Thompson B, Hendy P, et al. Exclusive enteral nutrition provides an effective bridge to safer interval elective surgery for adults with Crohn's disease. Aliment Pharmacol Ther. 2017;45(5):660-669. doi:10.1111/apt.13934
  4. Day A, Wood J, Melton S, Bryant RV. Exclusive enteral nutrition: An optimal care pathway for use in adult patients with active Crohn's disease. JGH Open. 2019 Sep 10;4(2):260-266. doi: 10.1002/jgh3.12256. PMID: 32280775; PMCID: PMC7144766
  5. Sood A, Singh A, Sudhakar R, et al. Exclusive enteral nutrition for induction of remission in anti-tumor necrosis factor refractory adult Crohn's disease: the Indian experience. Intest Res. 2020;18(2):184-191. doi:10.5217/ir.2019.00094
  6. Shaoul R, Brown S, Day AS. Reasoning Beyond the Potential Use of Exclusive Enteral Nutrition and Other Specified Diets in Children With Ulcerative Colitis. J Pediatr Gastroenterol Nutr. 2018;66(3):378-382. doi:10.1097/MPG.0000000000001785
  7. Sahu, P., Kedia, S., et al.  Randomised clinical trial: Exclusive enteral nutrition versus standard of care for acute severe ulcerative colitis. Alimentary Pharmacology & Therapeutics. (2021) https://doi.org/10.1111/apt.16249
  8. Souza, G. N. de, Draghi, P. F., & Yonamine, G. H. (2020). Oral and enteral nutrition therapy in inflammatory bowel disease among the pediactric population: A literature review. Revista Paulista de Pediatria, 38, e2019032. https://doi.org/10.1590/1984-0462/2020/38/2019032
  9. Levine A, Wine E, Assa A, et al. Crohn's Disease Exclusion Diet Plus Partial Enteral Nutrition Induces Sustained Remission in a Randomized Controlled Trial. Gastroenterology. 2019;157(2):440-450.e8. doi:10.1053/j.gastro.2019.04.021
  10. Yanai H, Levine A, Hirsch A, et al. The Crohn's disease exclusion diet for induction and maintenance of remission in adults with mild-to-moderate Crohn's disease (CDED-AD): an open-label, pilot, randomised trial. Lancet Gastroenterol Hepatol. 2022;7(1):49-59. doi:10.1016/S2468-1253(21)00299-5
Transistioning from EEN to a Therapeutic Diet
  1. Logan M, Clark CM, Ijaz UZ, et al. The reduction of faecal calprotectin during exclusive enteral nutrition is lost rapidly after food re-introduction. Aliment Pharmacol Ther. 2019;50(6):664-674. doi:10.1111/apt.15425
  2. MacLellan A, Moore-Connors J, Grant S, Cahill L, Langille MGI, Van Limbergen J. The Impact of Exclusive Enteral Nutrition (EEN) on the Gut Microbiome in Crohn's Disease: A Review. Nutrients. 2017;9(5):447. Published 2017 May 1. doi:10.3390/nu9050447
  3. Yang H, Feng R, Li T, et al. Systematic review with meta-analysis of partial enteral nutrition for the maintenance of remission in Crohn's disease. Nutr Res. 2020;81:7-18. doi:10.1016/j.nutres.2020.06.006
two bottles with liquid nutrition with straws in them.
Somebody in the kitch - view from the back while preparing healthy foods. Cutting board with various healthy foodsPink Milkshake and fruits on a white table and pink backgroundWoman stirring in a pot with vegetables.on the stove

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