Crohn’s Disease Exclusion Diet

Written By Darcy Ayton

A Structured Nutrition Therapy for Active Crohn’s Disease

The Crohn’s Disease Exclusion Diet (CDED) combined with Partial Enteral Nutrition (PEN) is a clinically developed dietary therapy used in selected patients with active Crohn’s disease to help reduce intestinal inflammation and support remission.

Unlike general dietary advice, CDED is not a lifestyle diet, it is a structured therapeutic protocol designed to modify specific dietary exposures while ensuring nutritional adequacy through both food and prescribed supplement drinks.

Why CDED is used:

CDED was developed as an alternative to exclusive enteral nutrition (EEN), a liquid-only nutrition therapy traditionally used to induce remission. While EEN can be effective, it can be difficult to maintain. CDED allows carefully selected whole foods alongside medical nutrition supplements, making it more sustainable for many patients while still targeting inflammation.

The approach is thought to work through several mechanisms:

  • Modifying dietary factors that may negatively influence the gut microbiome

  • Reducing exposure to certain food additives and processed foods

  • Providing nutrients that support gut barrier integrity

  • Maintaining adequate calorie and protein intake during active disease

  • Importantly, this diet aims to treat inflammation, not just symptoms.


CDED is delivered in phases so that the gut is supported during active disease and food variety can gradually increase as inflammation improves.

Phase 1 (Weeks 0–6)

The most structured phase. Approximately half of daily nutrition comes from prescribed supplement drinks. The food list is intentionally short and focuses on simple, minimally processed ingredients such as lean proteins, specific fruits, vegetables, and starches. This phase is designed to stabilise disease activity and support healing.

Phase 2 (Weeks 7–12)

Food variety increases while supplement drinks usually provide around a quarter of nutrition. Additional fruits, vegetables, and selected grains may be introduced gradually under dietetic guidance.

Phase 3 (Maintenance phase)

The final phase transitions toward a more varied, balanced diet. Supplement drinks may be reduced or stopped depending on individual needs, clinical status, and nutritional markers. Long-term dietary patterns are individualised based on tolerance, symptoms, and disease course.


Role of supplement drinks:

Medical nutrition supplements are a core therapeutic component of CDED. They help ensure adequate intake of:

  • Energy

  • Protein

  • Vitamins

  • Minerals

This is particularly important when appetite is reduced or dietary variety is temporarily limited.


Who should follow CDED?

CDED is not suitable for everyone with Crohn’s disease. It is typically considered in:

  • mild–moderate active disease

  • Patients motivated to follow a structured programme

  • Situations where nutritional therapy is appropriate alongside medical treatment

The decision to start CDED should always be made jointly with a gastroenterologist and an IBD dietitian.


The Crohn’s Disease Exclusion Diet is a structured, evidence-based nutritional therapy designed to reduce inflammation and support remission in Crohn’s disease. When used appropriately and with specialist guidance, it can be an effective component of multidisciplinary care.


Levine A. et al. Crohn’s Disease Exclusion Diet plus Partial Enteral Nutrition Induces Sustained Remission. Gastroenterology, 2019.

Levine A. et al. Dietary Guidance From the International Organisation for the Study of IBD. Gastroenterology, 2019.

ESPEN Guideline: Clinical Nutrition in Inflammatory Bowel Disease. Clinical Nutrition.

ECCO Guidelines on Nutrition in IBD. Journal of Crohn’s and Colitis.

Darcy Ayton