You're a lay person. You know there is a thing out there called 'foo'.

You've read things that compellingly claim that foo causes xyz symptoms. You also know that some people that have obviously palpable disdain for you claim that foo could never cause these symptoms.

You have xyz symptoms. Are you mentally ill if you think that foo could be the cause?

Are the compelling claims from experts in foo or xyz? Is the disdain?