Crohn’s Disease Exclusion Diet for Remission Induction in Adults: A Systematic Review and Stratified Synthesis

Background/Objectives: The Crohn’s disease exclusion diet (CDED) offers a structured nutritional strategy for adults with Crohn’s disease. We evaluated remission outcomes by comparator, assessment time, and analysis population to clarify its clinical interpretation. Methods: Six databases were searched from January 2014 to 2 September 2026. Week-6 clinical remission was primary; later assessments were secondary. Randomized comparisons were analyzed separately by comparator and time point. Uncontrolled proportions were reported individually using exact binomial confidence intervals. Risk of bias and certainty were assessed using design-specific tools. The protocol was registered in PROSPERO (CRD420261381711), with broader activity-range inclusion and exploratory analyses reported as deviations. Results: Seven studies comprised two randomized trials and five uncontrolled studies. At week 6, remission occurred in 13/19 participants receiving CDED plus partial enteral nutrition versus 12/21 receiving CDED alone (risk ratio 1.20, 95% confidence interval 0.74–1.94). A separate trial favored CDED over a Mediterranean diet at week 12 (17/24 versus 8/21; 1.86, 1.02–3.40). Comparative certainty was very low or low. Descriptive, exploratory uncontrolled week-6 remission proportions in clinically active populations were 30/48 (62.5%) and 23/30 (76.7%). Objective inflammatory outcomes were inconsistently assessed and showed no consistent comparative advantage accompanying symptomatic remission. Conclusions: Adult evidence identifies a symptomatic remission signal that differs by comparator and assessment time. Comparative biochemical or endoscopic superiority remains unestablished. This synthesis clarifies the population and treatment question represented by each estimate. Trials should assess inflammatory control, nutritional adequacy, adherence, and longer-term outcomes during treatment and after cessation.