A prospective randomized controlled study of erythromycin on gastric and small intestinal distention: Implications for MR enterography

Objectives: To assess if erythromycin increases gastric emptying and hence improves small intestinal distention during MR enterography. Methods: Gastric, small intestinal, and large intestinal volumes were assessed with MR after neutral oral contrast (1350 ml in 45 min) and balanced randomization to erythromycin (200 mg i.v., age 31 ± 3y, 13 females), or placebo (37 ± 3y, 13 females) in 40 healthy asymptomatic volunteers. Fat-suppressed T2-weighted MR images of the abdomen were acquired on a 1.5 T magnet at standard delay times for enterography. Gastric, small, and large intestinal volumes were measured by specialized software. In addition, two radiologists manually measured diameters and percentage distention of jejunal and ileal loops. Treatment effects were evaluated by an ITT analysis based on ANCOVA models. Results: All subjects tolerated erythromycin. MRI scans of the stomach and intestine were obtained at 62 ± 2 (mean ± SEM) and 74 ± 2 min respectively after starting oral contrast. Gastric volumes were lower (P < 0.0001) after erythromycin (260 ± 49 ml) than placebo (688 ± 63 ml) but jejunal, ileal, and colonic volumes were not significantly different. However, maximum (76-100%) jejunal distention was more frequently observed (P = 0.03) after erythromycin (8/20 subjects [40%]) than placebo (2/20 subjects [10%]). The diameter of a representative ileal loop was greater (P = 0.001) after erythromycin (18.8 ± 4.3 mm) than placebo (17.3 ± 2.8 mm) infusion. Conclusions: After ingestion of oral contrast, erythromycin accelerated gastric emptying but effects on small intestinal dimensions were variable. In balance, erythromycin did not substantially enhance small intestinal distention during enterography using current standard delay times.