there are tortoises and turtles tortoises live on land and turtles swim and sometimes live underwater

Yes - they also have an internal skeleton.

The Galapagos tortoise

A leopard tortoise. :)

The tortoise probably has something called a prolapsed cloacea. It needs to go to a veterinarian immediately. This is not only very painful, but it's also fatal if not properly taken care of. This can be caused by straining while having a bowel movement, laying eggs, a parasite or a tumor. Whatever the case is, it needs to be taken care of immediately, and preferably with a herpetologist veterinarian