Is diverticulosis considered a pre-existing condition?

Any disease including diverticulosis if exists before and/or at the time of filling up the proposal form for Medical Insurance will be deemed to be 'Pre-existing'. The pre-existing condition will be excluded from the purview of mediclaim for specific period which may vary from one Insurance company to other.However, if the insured person is unaware of existence of any disease like Gol bladder stone and did not mention in the proposal form, the same will not be treated as 'Pre existing'.