Paradoxical sphincter reaction and associated colorectal disorders

Area of Science:

• Gastroenterology
• Colorectal Surgery
• Neurogastroenterology

Background:

• Paradoxical sphincter reaction presents with diverse anorectal symptoms, including constipation, outlet obstruction, and incontinence.
• Understanding the underlying pathophysiology is crucial for effective patient management.

Purpose of the Study:

• To investigate the anorectal anatomy and physiology in patients with paradoxical sphincter reaction.
• To identify diagnostic markers and patterns associated with this condition.

Main Methods:

• Utilized defecography, colon transit time, anorectal manometry, and electromyography (EMG) in 71 patients.
• Assessed maximal anal pressure (MAP) and maximal squeeze pressure (MSP) to evaluate sphincter function.
• Examined EMG activity in the puborectalis muscle and external sphincter.

Main Results:

• Ninety-six percent of patients exhibited additional anorectal anatomical and physiological changes.
• Abnormal defecography was observed in 70%, and delayed colon transit time in 42% of patients.
• Decreased MAP and MSP suggested impaired anal sphincter function; EMG confirmed paradoxical reactions, with denervation more pronounced in the external sphincter and right pudendal nerve damage more frequent.

Conclusions:

• Paradoxical sphincter reaction is frequently associated with significant anorectal dysfunction.
• EMG is a sufficient diagnostic tool, with the absence of a normal closing reflex being key evidence.
• Sphincter dysfunction and nerve damage contribute to symptoms like incontinence in affected patients.