Contraction of puborectalis muscle produces anorectal angulation
Internal anal sphincter (IAS) contracts
External anal sphincter (EAS) contracts
Continence is maintained
Note:� For continence to be maintained the 𝘼𝙉𝙊𝙍𝙀𝘾𝙏𝘼𝙇 𝘼𝙉𝙂𝙀𝙇 must be less than 90 degrees.
�  �  The correct posture on the toilet is essential to relax the puborectalis muscle, widen the angle and open the canal.

The 𝘼𝙉𝙊𝙍𝙀𝘾𝙏𝘼𝙇 𝘼𝙉𝙂𝙀𝙇 is the angle created by a line drawn through the central axis of the anal canal and a line drawn through either the central axis of the distal rectum or a line drawn parallel to the posterior wall of the distal rectum. It can be measured at rest and during evacuation. Normal values range from 90° to 110° at rest. Normal values increase at evacuation.