Phenotypic variation in functional disorders of defecation

Area of Science:

• Gastroenterology
• Pelvic Floor Disorders
• Functional Bowel Diseases

Background:

• Obstructed defecation is often linked to pelvic floor dyssynergia.
• Clinical evidence suggests a broader range of anorectal issues in constipation.

Purpose of the Study:

• To characterize the phenotypic variability in constipated patients using comprehensive anorectal assessments.
• To identify distinct patient subgroups within functional defecation disorders.

Main Methods:

• Assessed anal pressures, rectal balloon expulsion, rectal sensation, and pelvic floor structure/motion using endoanal and dynamic MRI in constipated and asymptomatic women.
• Employed principal components analysis to characterize patient phenotypes based on these measurements.

Main Results:

• Significant abnormalities were found in anal pressures, rectal balloon expulsion, rectal sensation, and pelvic floor motion among constipated patients.
• Principal components analysis identified perineal descent during defecation, anorectal location at rest, and anal resting pressure as key discriminators.
• Increased perineal descent was associated with obesity, higher anal resting pressure, and normal rectal balloon expulsion.

Conclusions:

• Functional defecation disorders represent a heterogeneous group of conditions.
• Subcharacterization based on perineal descent, anorectal location, and anal resting pressure is possible.
• Further research is needed to explore the clinical implications of these identified phenotypes.