Background Data on the effectiveness of polymeric Exclusive Enteral nutrition (EEN) in inducing biochemical remission in adult patients with active Crohn’s disease (CD) is scarce. Our aim was to assess the effectiveness of polymeric EEN in inducing biochemical remission in adults with active CD.

Methods Single tertiary centre retrospective study of patients with active CD who received induction therapy with EEN from January 2018 to September 2022. Active CD was defined as CRP ≥ 10mg/L or faeces calprotectin (FC) ≥ 250mcg/g. Primary endpoint (PE) was biochemical remission at 8 weeks. Biochemical remission was defined as CRP < 6 mg/L in patients with CRP ≥ 10mg/L at baseline OR FC <150 mcg/g in patients with an FC ≥ 250mcg/g at baseline.

Results Sixty-one patients were included, 32 (52.4%) females, median age 53 years (IQR: 28-62). Median disease duration was 6 years (IQR: 1-20), median duration of EEN was 7 weeks (IQR: 5.5-8 weeks). 34 (55.7%) patients received steroids concurrently. PE was achieved in 35 (57.4%) patients overall; 20 (58.8%) with concurrent steroid and 15 (55.6%) without steroid use at baseline achieved PE, p=1. 43.7% (7/16) of patients with ileal, 50% (4/8) with colonic and 64.9% (24/37) with ileo-colonic (p=0.33) disease phenotype achieved PE. Significantly fewer patients with baseline concurrent biologic achieved PE [12/29 (41.38%) vs 23/32 (71.9%), p=0.021]. On univariable analysis, absence of biologic therapy at baseline was a predictor for achieving PE [OR 3.6 (1.23-10.6), p=0.019]. Age, disease location, age at diagnosis, behaviour, sex, disease duration, smoking status, concurrent steroid use or concurrent immunomodulator use did not predict achieving PE. 40 patients had CRP ≥ 10mg/L at baseline, of whom 25 (62.5%) achieved CRP < 6 mg/L. 49 patients with ≥ 250mcg/g at baseline, of whom 22 (45%) achieved FC <150 mcg/g. Conclusion Polymeric EEN is effective in inducing biochemical remission in adults with active CD irrespective of disease location or concurrent steroid use. Significantly fewer patients on concurrent biologics at baseline achieved biochemical remission.