I'm not entirely sure about the whole cancerous idea behind anal leakage. Just doing a back-bone research, it is a sign to possible cancer, but it doesn't always lead to cancer. Either way, it's always good to get it checked out before it's too late. I know it will be extremely awkward talking to your parents about health problems, but they are there to help. Regardless, they won't judge you or think any differently. You're still their child, and it's not like you can control what is happening to you. I know that it is hard to hear that you are wrong, especially from a parent. They should still care. If you truly feel that they could possibly be giving you a fault answer, then nothing is stopping you from going to another doctor besides your parents. Perhaps this will enable you to open up and explain into more detail what's going on, without the fear of your parents knowing everything. I would strongly recommend going to a doctor especially if you had a STD fear. Just go to a health clinic or where ever they offer STD checks, and try to get one done. It's simple, affordable, and would put the idea behind you (hopefully.) No loss, only gain from this idea.
It's completely understandable to be afraid and scared of what's happening to you. I would be too. You have every right to be concerned and every right to want to know exactly what is happening. Is there any possible way of you getting there without your parents taking you? Perhaps you could make up an excuse to a friend saying you need to go visit someone in the hospital, but your parents won't take you. Money could be an issue, but you are always under your parents health care. Just try have another reasonable conversation with them. They have to budge sooner or later. Definitely if you feel that your life could be in danger.
~Wayne
-------
₪This mix could burn a hole in anyone.₪