I would be very surprised if they attempted to withdraw an offer of employment on that basis. If it's in the past and dealt with you should have nothing to worry about. If/when someone ticks a yes in answer to any of the vast number of questions on these questionnaires, what the employer will be looking for either in the 'further information' box or in further conversations about the issue, will be reassurance that at this time you are fit as a fiddle, raring to go and are not likely to have huge amounts of time off.
My employer (last public sector) use pre-employement medical questionnaires. They use them to assess what they are taking on, any special needs, and for the pension provider. They don't use them to withdraw an offer of employment. Not sure that they could since the questionnaires are not done until the offer stage, not the interview stage. The last question on our is "Are you pregnant ?" - and are true to job offers even when the answer is "yes".