Number 2: how does it work?

Number 2: how does it work?

Everybody goes to the loo (even princess!), but do you know how does it work? How does your body can on command hold on for hours and empty when the appropriate time appears?  


First let’s see why we are not force to wear diaper and we can wait more than 5 minutes to go to the loo. Put in other words, how does continence work? Continence is possible through two different systems:
  • Rectum is the end of the digestive tract and the final container
  • Sphincter muscles composed of sphincter ani (internus and externus) and levator ani enable a complete closure of the anus
For more details have a look at our previous article on pelvic anatomy. Thanks to sensitive receptor in rectal wall, we are able to perceive when it is full (sensation of need to go to the loo) and also the nature of the content (gas, liquid or solid faeces)
Rectum and anus anatomy
Rectum and anus anatomy
As faeces arrive in the rectum, internal anal sphincter relaxes allowing them to move in the anal canal and external anal sphincter engage to maintain anal continence. At this point there are two possibilities:
  • You can go to the loo. External sphincter is voluntarily relaxes triggering a complete emptying.
  • You can’t go to the loo. A voluntary contraction of external sphincter for a minute will give time to the rectum to adapt to the new volume and stretch its wall. The need to go consequently disappear and the internal sphincter is engaged again


How to sit correctly on the loo?
  • When sitting or even better squatting, the rectum is aligned with the anus
  • It also relaxes both levator ani and external anal sphincter muscles
  • Consequently, faces can be easily eliminated
  • At the end of defecation, a rapid contraction of levator ani and external anal sphincter muscles close the angle between rectum and anus
Have a look at our previous article on Constipation for more details on how to sit correctly on the loo!

Mechanisms of Anal incontinence

Different mechanisms can lead to anal incontinence: 1) When external sphincter or pelvic floor muscles are teared, voluntary contraction is not possible anymore. Consequently, faeces entering the rectum can’t be retained and their final elimination delayed. It’s called anal incontinence. 2) Rectum is a compliant container where faeces are kept temporarily, allowing to postpone their elimination. However, if this rectal compliance is diminished the capacity of this container is in turn reduced shortening the time between two visits to the loo. 3) On the contrary, if the rectal compliance is increased or if rectal sensibility is impaired, faeces can pileup and lead to anal incontinence by congestion. 4) Finally, traumas impacting rectum position (like in exteriorized prolapse due to long delivery or use of forceps) and consequently its function are another cause of anal incontinence.

Pelvic Floor Dyssynergia / Anal Sphincter Dyssynergia

What is it?

It is an incapacity for the anal sphincter to relax during defecation or even a spasm of this muscle which can be associated to a spasm of other pelvic floor muscles (levator ani). As defecation is impossible, it causes an anal constipation. The absence of anal sphincter relaxation is often associated to an incorrect abdominal push.

How to treat it?

The aim is to maintain anal relaxation in defecation. It can be achieved by working with a Biofeedback. Have a look at our previous post for more details about this treatment. Learning to have a good breathing pattern and how to use abdominal muscles to push correctly: breathing out in a close fist or in a straw to slow down exhalation help to relax anal sphincter. In the contrary, pushing as your holding your breath (even more after deeply breathing in) will cause an important increase of pressure pushing on a none relax/closed anal sphincter: it is a cause of prolapse. Don’t hesitate to speak to your GP, gynaecologist or women’s health physiotherapist for more details about incontinence issues and their treatments.

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