Bought house to flip, suspect mold.

[Michael Held]

We recently closed on a house to upgrade and flip but even though there is no apparent mold and the inspection did not find any, we suspect that there is possibly mold or some other airborne agent in the home due to the fact that one person seems to be affected whenever they spend any time in the house (they are very susceptible to many things most people are not) . All other people (myself, friends, subs, etc.) who have been in the home have not had any issues. 

Should we conduct mold tests prior to remodel and then have to deal with any possible remediation or are we liable in any way if we do not and issues are found when we put it on the market or after sale?