Is there any reason you need to disclose your disability in the interview? The only time you should disclose it is if you are requesting accommodations for your disability. Otherwise why do they need to know? You aren’t required to disclose at all. It’s nothing to do with being honest. Would you talk about your hypothetical diabetes or IBS or kidney stones on the interview? If you are honest, you must disclose everything then. How was it relevant to the interview?