Objective MRI is increasingly used to evaluate small bowel contractility. The objective of this study was to validate a clinically practical stimulation test (300‐kcal meal) for small bowel motility. Methods Thirty‐one healthy subjects underwent dynamic MRI to capture global small bowel motility after ±10h fasting, of which 15 underwent bowel preparation consisting of 1 L 2.5% mannitol solution and 16 did not. Each subject underwent (1) a baseline motility scan (2) a food challenge (3) a post‐challenge scan, and (4) second post‐challenge scan (after ±20 minutes). This protocol was repeated within 2 weeks. Motility was quantified using a validated motility assessment technique. Key Results Motility in prepared subjects at baseline was significantly higher than motility in unprepared subjects (0.36 AU vs 0.18 AU, P < 0.001). In the prepared group, the food challenge produced an 8% increase in motility (P = 0.33) while in the unprepared subjects a significant increase of 30% was observed (P < 0.001). Responses to food remained insignificant (P = 0.21) and significant (P = 0.003), for the prepared and unprepared subjects, respectively, ±20 minutes post food challenge. These results were confirmed in the repeated scan session. Conclusion & Inferences A significant response to a 300‐kcal meal was measured within 10 minutes in unprepared bowel, supporting the clinical use of this challenge to provoke and assess motility changes. A caloric challenge did not produce an observable increase in motility in mannitol prepared subjects.

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Background: Structured evaluation of magnetic resonance imaging (MRI) is important to guide clinical decisions of perianal fistulas in Crohn's disease (CD) patients. Purpose: To evaluate the recently developed modified Van Assche index to assess clinical responses to anti-tumor necrosis factor (TNF) therapy in patients with perianal fistulizing CD. Methods: A search of medical records identified patients with fistulizing perianal CD who underwent baseline and follow-up MRI while receiving anti-TNF treatment. Patients were divided into clinical responders and nonresponders based on physician's assessment. MRI-scans were scored using the original and modified Van Assche index and scores between baseline and follow-up were compared within clinical responders and non-responders. Results: Thirty cases were included (48% female, median age 27 years). Clinical responders (n = 16) had a median modified Van Assche score of 9.6 (IQR 5.8-12.7) at baseline and 5.8 (IQR 3.5-8.5) at follow-up (p = 0.008). In non-responders (n = 14), corresponding scores were 7.7 (IQR 5.8-13.5) and 8.2 (IQR 5.8-11.5) (p = 0.624). In clinical responders, 6/16 showed no drop in modified Van Assche score at follow-up. Scores obtained with the original Van Assche index dropped between baseline and follow-up in clinical responders (13.0 vs. 9.6, p = 0.011), whereas no decrease was observed in non-responders (11.5 vs. 11.5, p = 0.324). Conclusions: While the modified Van Assche index overall decreases significantly in patients with perianal fistulas responding to anti-TNF treatment, one third of responders had unaltered scores at follow-up. Also, outcomes were comparable to the original Van Assche index. Further optimization of the modified Van Assche index is needed before application in larger studies. Recently, Samaan et al. modified this index to increase objective reflection of clinical responses and in order to improve interrater and