use the toilet

verb2

1. •
   (euphemistic) To urinate, defecate, or both in a toilet.

   • She'll be right back. She had to use the toilet.
2. •
   (euphemistic) To urinate, defecate, or both in other places.

   • We had to use the toilet in the woods when we went camping, so we carried bog rolls and small shovels everywhere we went.