I think I may have responded already but in addition to payment protection insurance being an optional product by law ( refer to ICOB rules as prescribed by the FSA ) , the chances of the insurance paying out on a pre existing condition are slim to none, so the fact they have had past health problems means nothing as far as the cover is concerned - essentially they would not be covered if the previous health problems returned anyway - always check the policy for exclusions and limitations.

 If you need any further info message me back.