doctor says i have a parasite, this after doing P&B shakes for 3 weeks

I've had a stomach ache for 3-4 weeks .... went to dr today, he thinks i have a parasite. I did do P&B shakes (after a liver flush) for 3 weeks starting about 5 weeks ago ..... is that somehow related to the parasite? i haven't been out of the country, etc ... so he has no idea how i could have gotten it.

he put me on an anti- parasite antiobiotic.