Colonic Volume Changes in Paediatric Constipation Compared to Normal Values Measured Using MRI

Abstract

Background: Functional constipation in children is common. Management of this condition can be challenging and is often based on symptom reports. Increased, objective knowledge of colonic volume changes in constipation compared to health could provide additional information. However, very little data on paediatric colonic volume is available except from methods that are invasive or require unphysiological colonic preparations.

Objectives: (1) To measure volumes of the undisturbed colon in children with functional constipation (FC) using magnetic resonance imaging (MRI) and provide initial normal range values for healthy controls, and (2) to investigate possible correlation of colonic volume with whole gut transit time (WGTT).

Methods: Total and regional (ascending, transverse, descending, sigmoid, and rectum) colon volumes were measured from MRI images of 35 participants aged 7-18 years (16 with FC and 19 healthy controls), and corrected for body surface area. Linear regression was used to explore the relationship between total colon volume and WGTT.

Results: Total colonic volume was significantly higher, with a median (interquartile range) of 309 mL (243-384 mL) for the FC group than for the healthy controls of 227 mL (180-263 mL). The largest increase between patients and controls was in the sigmoid colon-rectum region. In a linear regression model, there was a positive significant correlation between total colonic volume and WGTT (R = 0.56, p = 0.0005).

Conclusions: This initial study shows increased volumes of the colon in children with FC, in a physiological state, without use of any bowel preparation. Increased knowledge of colonic morphology may improve understanding of FC in this age group and help to direct treatment.

Keywords: MRI; children; colon; constipation; transit; volume.

Figure 1

3D representations of the colon morphology from four different participants whose characteristics were: (a) patient, 13 years old, weight 42 kg, height 154 cm, BMI 17.7 kg/m², total colon volume (TCV) = 712 mL, whole gut transit time (WGTT) = 140 hs; (b) healthy control, 17 years old, weight 80 kg, height 185 cm, BMI = 23.4 kg/m², TCV = 360 mL, WGTT = 16 hs; (c) patient, 9 years old, weight 48 kg, height 130 cm, BMI 21.4 kg/m², TCV= 237 mL, WGTT = 75 hs; (d) healthy control, 10 years old, weight 42 kg, height 145 cm, BMI = 19.9 kg/m², TCV = 227 mL, WGTT = 26 hs.

Figure 2

Total colon volume corrected for both body surface area of n = 19 controls and n = 16 patients with constipation. The horizontal lines indicate the median, * p = 0.0081 two-tailed Mann–Whitney test.

Figure 3

Regional colon volumes corrected for body surface area (ascending colon (AC), transverse colon (TC), descending colon (DC), sigmoid colon and rectum (SC-R)) for 19 controls and 16 patients with constipation. The box-and-whiskers plot shows the mean (+) and median (−) values of the regional ascending, transverse, descending, and sigmoid colon and rectum volumes. The box represents the 25th–75th centile, and the whiskers represent the 10th–90th centile ranges, respectively. * p = 0.0410 one-tailed Mann–Whitney test.

Figure 4

Correlation between whole gut transit time (WGTT) and total colonic volume, corrected for body surface area, for 19 controls and 16 patients with constipation coefficient of correlation R = 0.56, p = 0.0005.