High-resolution anorectal manometry in children with constipation-associated fecal incontinence

Functional constipation with retentive fecal incontinence indicates disturbed anorectal sensation, sphincter function, and defecatory coordination. High-resolution anorectal manometry (HR-ARM) evaluates anorectal sensorimotor function; however, pediatric reference data remain limited, particularly for Middle Eastern populations. To assess anorectal sensorimotor functions in children suffering from constipation and retentive fecal incontinence, using HR-ARM. In addition to contextually compare findings with published pediatric data, and to explore associations with demographic and nutritional status. One hundred eight children aged 4-15 years who met Rome IV criteria for functional constipation and fecal incontinence underwent standardized HR-ARM. Pressure, sensory, and coordination parameters were descriptively compared with published pediatric data. The principal reference study used 3D-HRARM rather than conventional HR-ARM, so, our comparisons were treated as contextual rather than direct interchangeable normative comparisons. Associations with age, sex, and nutritional status were assessed. Mean age was 9.7 ± 3.2 years (50.0% male, 50.0% female). Underweight and stunted were found in 21.3% and 23.1% respectively. Resting anal pressure (64.7 ± 24.8 mmHg) and squeeze pressure (106.0 ± 43.7 mmHg) were lower than the published reference values. First rectal sensation, first urge volume, and maximum tolerable volume were higher than the published reference values. The defecation index averaged 2.1 ± 0.9, with 10.2% falling below the dyssynergia-suggestive threshold of 1.0. Older age correlated with higher resting anal pressure (r = 0.24, p = 0.011) and a lower (more sensitive) first rectal sensation threshold (r = - 0.20, p = 0.037). No HR-ARM parameter differed significantly by nutritional status (underweight or stunting) or by sex.

Children with constipation-associated fecal incontinence show reduced anal pressures and markedly elevated rectal sensory thresholds, with a manometric pattern that may suggest dyssynergic defecation. Anorectal sensorimotor findings showed a modest age-related maturation pattern. HR-ARM defines a physiological profile that can guide individualized, mechanism-based treatment.

• Functional constipation-associated fecal incontinence is associated with anorectal sensorimotor dysfunction. This impairs quality of life in children. • High-resolution anorectal manometry (HR-ARM) is used to evaluate anorectal function, but pediatric HR-ARM reference data remain limited, and anorectal manometric data from children in Middle Eastern populations are particularly scarce.

• Egyptian children with constipation-associated fecal incontinence demonstrated markedly reduced anal resting and squeeze pressures, with high rectal hyposensitivity compared with published pediatric reference data. These cross-study differences are interpreted as contextual because the principal reference study used 3D-HRARM. • HR-ARM abnormalities were independent of sex and nutritional status. This supports individualized, mechanism-based management guided by physiological phenotyping.