Rectoanal sensorimotor response in humans during rectal distension

Area of Science:

• Gastroenterology
• Physiology
• Neurogastroenterology

Background:

• Rectal perception is crucial for maintaining continence and facilitating defecation.
• The relationship between rectal sensory perception and motor activity in the anorectum remains incompletely understood.

Purpose of the Study:

• To investigate the association between rectal distention, sensory perception, and motor responses in the anorectum.
• To characterize the sensorimotor responses during rectal distention in healthy individuals.

Main Methods:

• Utilized stepwise graded rectal balloon distensions in 23 healthy subjects.
• Employed a six-sensor probe for anorectal manometry, assessing rectoanal reflexes and sensory thresholds.
• Ensured reproducibility through repeat studies in a subset of participants.

Main Results:

• Rectal perception correlated with an anal contractile response, termed the sensorimotor response.
• The sensorimotor response was observed with sensations of fullness or the desire to defecate.
• The sensorimotor response associated with an urge to defecate exhibited significantly higher amplitude and area under the curve compared to the response with a mere desire to defecate.
• High reproducibility of the sensorimotor response was demonstrated.

Conclusions:

• A distinct, consistent, and reproducible sensorimotor response accompanies the desire to defecate.
• This sensorimotor response likely plays a key role in regulating anorectal sensation and function.
• Understanding this response offers insights into normal anorectal physiology.