Normative Measures of Colon Length and Width in Healthy Children Based on CT

Abstract Background To provide normative data on colon length and width in healthy children using 3-dimensional(3D) multiple-point computed tomography(CT) measurements, which may serve as reference values for identifying anatomic abnormalities in children with therapy-resistant constipation(TRC). Methods We conducted a single-center retrospective study of children aged 0–17 years, who underwent abdominal CT for trauma or abdominal pain in the emergency department of a tertiary care hospital in 2024. Children with anatomic or functional colonic abnormalities were excluded. The primary outcome was total colon length(cm). Secondary outcomes included total colon length/BSA(cm/m²), rectosigmoid length(cm), rectosigmoid length/BSA(cm/m²), rectal width(cm), and sigmoid width(cm). Descriptive statistics and linear regression were applied, with p < 0.05 considered significant. Results Of 244 children, 162 met inclusion criteria. Median age was 11 years [IQR:7–15], 88 (54%) were boys, median BMI was 20kg/m² [IQR:17–26], and median BSA was 1.4m² [IQR:1.0–1.7]. Mean total colon length was 103 ± 19cm (± 2SD:65–141 cm). Median total colon length/BSA was 76cm/m² [IQR:63–93], rectosigmoid length 32cm [IQR:26–40], rectosigmoid length/BSA 24cm/m² [IQR:18–31], rectal width 2.7cm [IQR:2.2–3.4], and sigmoid width 2.5cm [IQR:2.2–3.1]. In univariable analyses, colon lengths and rectal width were associated with age, height, weight, and BSA. In multivariable analysis, only BSA was independently associated with total colon length. Conclusions This study provides normative pediatric colon length and width data derived from abdominal CT. Colon lengths > 141cm and rectal widths > 3.4cm may be considered atypical. These reference values may facilitate evaluation of anatomic abnormalities in children with colonic dysmotility.