Study of the effect of temperature on the rectal function with evidence of thermorectal reflex

Abstract

Warm saline appears to cause rectal relaxation and cold saline rectal contraction. Subjects did not perceive sensation of warmth in the rectum but felt cold sensation, which may indicate the presence of cold receptors in the rectal wall. The rectal response to temperature variations is suggested to be reflex in nature as evidenced by its absence on rectal anesthetization. Such reflex, designated "thermorectal reflex," is proposed to mediate the rectal response and is speculated to have clinical significance in rectal dysfunctional and neurogenic disorders.

Rectal Heat Thresholds

“…19 The afferents to these mechanoreceptors are C or A␦ fibers. 9 Our thermal probe design is safe, compact, and has a high degree of subject comfort and acceptability. 22 We demonstrate a strong correlation between rectal heat thresholds and threshold volumes for defecatory desire and maximum toleration on balloon distention.…”

“…5 In the lower gastrointestinal tract, the anal canal is highly sensitive to temperature changes. 9 The first aim of this study was to evaluate the sensory response to heat stimulation in the rectum using a specially designed thermal probe over a wider range of temperatures than previously used. 7 Early studies investigating rectal sensation to thermal stimulation were able to elicit only a negligible response.…”

Importance of colonic transit evaluation in the management of fecal incontinence

“…Prior to initiating conservative treatment it should be a strict rule to exclude all other possible causes of incontinence. Only the exclusion of surgically treatable causes allows a conservative treatment [14,15,16]. Routine colonic transit time measurement in patients with fecal incontinence cannot yet be recommended.…”