Values From Three-dimensional High-resolution Anorectal Manometry Analysis of Children Without Lower Gastrointestinal Symptoms

BACKGROUND & AIMS: Three-dimensional high-resolution anorectal manometry (3DHRAM) provides a topographic image of pressure along the anal canal. We aimed to determine normal 3DHRAM values in children. METHODS: We performed a prospective study of 61 children (34 male; mean age, 8.28 years) without any symptoms arising from the lower gastrointestinal tract who were evaluated at the Department of Pediatric Gastroenterology and Nutrition, Medical University of Warsaw, Poland. Manometry procedures were performed by using a rigid probe without medication. Pressure within the anal canal and 3D images of sphincters were measured. If possible, squeeze pressure and thresholds of sensation were evaluated. The population was divided into age groups of <5 years, 5-8 years, 9-12 years, and older than 12 years. RESULTS: The mean resting and squeeze sphincter pressures were 83 +/- 23 mm Hg and 191 +/- 64 mm Hg, respectively. The mean length of the anal canal was 2.62 +/- 0.68 cm and correlated with age (r = 0.49, P < .0001). The mean rectal balloon volume to elicit rectoanal inhibitory reflex was 15.7 +/- 10.9 cm(3). The first sensation, urge, and discomfort were observed at balloon volumes of 24.4 +/- 23.98 cm(3), 45.9 +/- 34.55 cm(3), and 91.6 +/- 50.17 cm(3), respectively. The mean resting pressure of the puborectalis muscle was 69 +/- 14 mm Hg, whereas the mean squeeze pressure was 124 +/- 33 mm Hg. There was no statistically significant difference in pressure parameters between age groups. We observed a positive correlation between age and balloon volume needed to elicit discomfort (r = 0.49, P < .001). CONCLUSIONS: In a prospective study, we determined normal values from 3DHRAM analysis of children without symptoms arising from the lower gastrointestinal tract. There were no significant differences in pressure results between children of different sexes or ages.