Association Between Nutritional Status at Admission and Inadequate Bowel Preparation in Inflammatory Bowel Disease Patients: A Retrospective Cohort Study

Why It Matters

Identifying malnourished IBD patients before colonoscopy can prevent suboptimal visualization, reduce repeat procedures, and lower overall healthcare costs.

Key Takeaways

• Malnutrition prevalence in IBD patients ranged 6.3%–28% across three indices
• NRI, PNI, and NRS each doubled odds of inadequate bowel preparation
• NRI showed highest predictive accuracy, raising AUROC to 0.751
• Adding NRI to clinical models improved risk reclassification for poor prep
• Routine admission nutrition screening can personalize colonoscopy preparation strategies

Pulse Analysis

Malnutrition is a well‑documented comorbidity in inflammatory bowel disease, affecting up to one‑third of patients depending on the assessment tool used. Poor nutritional status compromises intestinal motility, muscle strength, and immune function, all of which can hinder the effectiveness of standard bowel‑cleansing protocols. As colonoscopy remains the gold standard for disease monitoring, surveillance, and therapeutic decision‑making in IBD, inadequate preparation not only obscures mucosal lesions but also drives repeat procedures, increasing patient burden and healthcare expenditures.

The Frontiers in Nutrition study leveraged a sizable retrospective cohort to quantify this relationship. By applying the Prognostic Nutritional Index, Nutritional Risk Index, and Nutritional Risk Screening within 48 hours of admission, researchers demonstrated that each metric independently predicted inadequate bowel preparation, with adjusted odds ratios hovering around two. Notably, the Nutritional Risk Index outperformed its counterparts, delivering a statistically significant rise in the area under the receiver‑operating‑characteristic curve—from 0.598 to 0.751 when added to a fully adjusted clinical model. Restricted cubic spline analysis further revealed a nonlinear dose‑response, underscoring that incremental declines in NRI scores translate into disproportionately higher prep failure risk.

These findings carry immediate clinical relevance. Incorporating a simple, inexpensive NRI calculation into pre‑procedure workflows enables gastroenterology teams to flag high‑risk patients and modify cleansing strategies—such as employing split‑dose regimens, higher‑volume solutions, or adjunctive pro‑kinetic agents—before the colonoscopy. Beyond procedural efficiency, early nutrition screening aligns with broader IBD management goals, prompting timely dietary interventions that may improve overall disease outcomes. Prospective, multicenter validation will be essential, but the evidence positions nutritional assessment as a pragmatic lever to enhance colonoscopy quality and reduce downstream costs in the IBD population.