Rectal stretch receptor

Rectal stretch receptors are specialized mechanoreceptors located within the smooth muscle and mucosal layers of the rectal wall. Their primary biological function is to detect distension caused by the accumulation of fecal matter, which triggers the defecation reflex and provides the conscious sensation of rectal fullness [1, 2, 5]. At the molecular level, these receptors rely on mechanosensitive ion channels, most notably PIEZO2, to convert mechanical stretch into electrical signals transmitted via the pelvic and pudendal nerves to the sacral spinal cord and brain [7, 10, 11]. Dysfunction of these receptors is central to several gastrointestinal disorders; for instance, hypersensitivity is a hallmark of Irritable Bowel Syndrome (IBS), while hyposensitivity contributes to chronic constipation and fecal incontinence [6, 11, 17]. Pharmacological modulation of these receptors or their downstream pathways is a key strategy in treating motility disorders, with drugs like linaclotide and prucalopride indirectly influencing their activity by altering gut transit and fluid secretion [16, 18]. Emerging research also highlights PIEZO2 as a potential direct therapeutic target for managing visceral pain and hypersensitivity [4, 9].

Other names

Rectal mechanoreceptorRectal wall stretch receptorRectal distension receptorMechanoreceptors of the rectum

Activation of mechanosensitive ion channels, primarily PIEZO2, in response to mechanical distension of the rectal wall, which triggers afferent neural signaling to the sacral spinal cord and cerebral cortex to initiate the defecation reflex and signal the urge to defecate.