Thanks for that clarification. Presuming that it is possible for one day to be happier than another, and that "happy" here doesn't imply a superlative state, then I sure would be happier without kidney disease than with it!
But back to the more basic and at the same time more urgent point to be clear about: Happiness, which is what Epicurus says we do everything to obtain, does not require complete absence of pain.
Are we agreed on that?