The active pushing phase can be felt differently as the baby moves further down the birth canal to be born. The sensations can be divided into the:
Early pushing, pressure sensations
Calling your doctor
Middle pushing, pressure to burning
End of pushing 'burning' sensations
Calling your doctor
Early pushing, pressure sensations. As you start pushing, the sensation of pressure in your bottom (mixed with pain) can be felt as the baby starts to descend into the vagina. For most of the active pushing phase this amazing sensation intensifies, but nothing can be seen yet when looking at the woman's genitals.
The anal pressure can feel similar to wanting to open your bowels. This causes many women to become confused and frightened, if they are not prepared for this sensation. Your body senses the baby in this way because you have many more sensitive nerves in your anus than you do inside your vagina. This, as well as the bowel and anus being very close to the vagina (only separated by thin layers of body membranes), makes it feel like the baby is coming 'out of your bottom', instead of your vagina, where the baby actually is.
If you expressed a desire to go to the toilet to open your bowels (as many women do!), your caregiver would more than likely discourage you, (unless they are happy for you to push on the toilet), as this is one sign to them that the baby's head is coming down.
Many women try to feel their baby's head during the pushing phase. This can help them keep in touch with how they are progressing. If you were to put your index finger into your vagina at this point, you would need to insert your finger in as far as where your finger meets the palm of your hand to touch your baby's head. If the waters have not broken yet, you would probably feel the bag of waters lower in the vagina, feeling more like a spongy balloon.