Rectal measurements and their correlation with bowel habits: Evaluation by trans-abdominal ultrasound in children with functional constipation

Aim: Constipation is one of the most common complaints in childhood affecting the quality of life of both children and parents. This study intends to investigate rectal measurements on ultrasound and their relationship with bowel habits. Methods: In this cross-sectional study, 100 children with functional constipation (FC) referred to a single hospital between 2018 and 2019 were enrolled. After obtaining informed consent, a questionnaire including demographic and constipation characteristics was completed, and a physical examination including digital rectal examination (DRE) was performed. Complete abdominopelvic ultrasound was then performed. Target measurements included rectal transverse diameter (RTD), rectal anterior wall thickness (RAWT) and the presence of faecal impaction. Results: One hundred children with a mean age of 7.68 +/- 3.30 years were present in the study. The mean duration of constipation was 15.86 +/- 13.34 months. In 14% of children, painful defaecation was reported. 88% of children had some degree of faecal incontinence. According to the ultrasound findings, the mean RTD and RAWT were 3.39 +/- 0.73 cm and 2.77 +/- 0.68 mm, respectively, and faecal impaction was present in 70% of cases. There was a positive correlation between RTD and RAWT with age, duration of constipation and the presence of hard stools, and there was a negative correlation with frequency of defecation (P < 0.05). Conclusion: RTD and RAWT increased with increasing constipation duration and the presence of hard stools and decreased with increasing frequency of defaecation. DRE could be omitted from the initial clinical assessment if you had access to reliable ultrasound data.