Well Sharancs...some people are adamant about the preparation and some people jump right away into flushing with no problems. It's different for everyone.
If you're itching to do it because you're in pain, I say do it right away. Then start your parasite cleanse right after it (Paragone, you can buy at your health/vitamin store) and continue parasite cleansing for at least a month. Keep flushing every 2 weeks...unless you feel achey again, then flush right away.