Prospective Evaluation of Individualized Nutrition Support on the Incidence of High-Output Ileostomy

Background: Patients with an ileostomy are at risk of developing a high-output ileostomy (HOS). An episode of HOS can lead to dehydration and acute kidney injury (AKI). Existing dietary recommendations are largely based on expert opinion. At Charité—Campus Benjamin Franklin, a new interdisciplinary nutrition concept was developed for patients following ileostomy creation. Methods: This prospective, single-centre interventional study included adult patients undergoing elective surgery with the creation of an ileostomy between July 2022 and November 2024. The primary outcome was the incidence of post-discharge HOS occurring during the follow-up period. Patients received standardized postoperative meals and individualized dietary counselling. Outcomes were compared to a historical cohort. Results: Among 103 patients (44.2% female; median age 47.5 years), HOS occurred in 13 patients (12.6%; 95% CI 6.8–20.4%) during follow-up and in 41 of 296 patients in the historical cohort (13.9%; 95% CI, 10.4–18.3%). Patients (n = 23) developing HOS during hospitalization experienced no recurrence at follow-up. Readmission was more frequent in the HOS group (53.8% vs. 21.1%, p = 0.011), particularly due to AKI (46.2% vs. 5.6%, p < 0.001). Weight loss was also more common during follow-up in the group with HOS (76.9% vs. 35.6%, p = 0.005), with a median weight loss of 2 kg. Conclusions: HOS incidence was not different from that observed in the historical cohort; however, the study was not designed to establish equivalence or non-inferiority. The structured nutrition pathway was feasible to implement. Post-discharge HOS was associated with readmission, acute kidney injury, and weight loss.