If you spend hours in the toilet despite taking stool softeners, you might be suffering from Anismus. This condition involves the paradoxical contraction of the puborectalis muscle during defecation. In this article, I discuss the physiology of anismus.
Anatomical Mechanism
The puborectalis muscle loops around the rectum, maintaining fecal continence by creating the anorectal angle. During defecation, this angle must straighten as the muscle relaxes. In anismus, the muscle tightens instead, acting like a locked door.
Patient Demographics
It is commonly observed in individuals under high stress, those with strict childhood toilet training, or patients with chronic pelvic pain syndrome.