Hi Indianajones, I haven't bought a zapper yet and so I'm trying to get enough info to determine which is the best. While doing the research I have found there are many options out there and its a little confusing. No illness in particular prompted me to do this. I had been wanting to cleanse for a while and I do experience IBS symptoms. While searching for cleanses, I came across Hulda Clark 's method and thought her theory regarding parasites to be plausible and so thought that I might be thorough and zap as well. Given the number of people that are most likely infected to varying degrees I thought it might be a good idea! :)