Avocado birth

When you are at the latest stage of a massive constipation. You know it's there. You know it wants to get out. But the form and shape of it, has left the stage where you can call it 'feces' a long, long time ago.

It has turned into the form and shape of a huge, unripe avocado. It's coming. You just have to get it out, and you have no enema to help you. The avocado birth is there. It's coming and it's unavoidable. You have no other option than to just do it. Pain. Pain.

At a surprise party where lot's of really nice people have arrived and just waiting for you. They ask eagerly: "Where's Zed, where's Zed?"
Friend answers: "He's coming. He's just doing an avocado birth"