Students may not eat during exams, but they may drink water using a sealed water bottle as opposed to an open cup to avoid spillage. Students may also drink water from a clear cup. 

However, the learner will be held responsible for any incidents that negatively affect learner performance or results such as damage or interruption to equipment due to spillage.

If you need to go for a toilet break, this should only be done if absolutely necessary.  Remember that you will be monitored via your webcam, so absences will raise alarms.  In addition, your time allowed will remain the same for the exam session, and will not pause while you are away.