Colon Length in Children, Normal Values Based on Magnetic Resonance Imaging

Background Currently, dolichocolon and dolichosigmoid lack objective definitions. As a result, diagnoses rely on subjective clinical judgment, though these conditions significantly impact decision making in children with therapy-resistant constipation. Objective To establish normative data on colon lengths in children without constipation using a three-dimensional multiple-point measurement (3D MPM) technique on magnetic resonance imaging (MRI. Methods This retrospective study included children aged 0–17 years who underwent MRI enterography in 2016 or 2020 for suspected inflammatory bowel disease (IBD) but did not meet Rome IV criteria for functional constipation. Patients with colonic inflammation on MRI or endoscopy were excluded. Primary outcome was the mean total colon length (± 2SD); secondary outcome was the mean rectosigmoid length (± 2SD). Two authors independently measured colon segments on coronal T2-weighted MRI using 3D MPM in syngo.via VB60S_HF90 (Siemens Healthineers). Linear regression was used to evaluate associations with age, height, weight, and body surface area (BSA). Results Eighty-one children (median age 15 years; range 11–17; 53% male) were included. Mean total colon length was 115.8 ± 13.8 cm; mean rectosigmoid length was 38.2 ± 7.9 cm. Colon length significantly correlated with age (p = 0.03), height (p < 0.001), weight (p < 0.001), and BSA (p < 0.001). Conclusion This study offers normative data on colon and rectosigmoid lengths in children without constipation. These values may serve as reference standards for diagnosing dolichocolon and dolichosigmoid in children with therapy-resistant constipation.