Yes, www.drizasgworld.com is the only website for that. As it comes with alot of features including,

1. only verified doctors are inside the portal ensuring you are communicating only with them.
2. you can set privacy across the departments like cardio , neuro , dental, ophtalmo , nephro , vet , human and more.
3. Can connect with verified medical professionals cross the globe.
4. you can also hide your identity while posting. (For any or many reasons)  That wont be revealed unless ethical or legal issues happen*

but what ever knowledge you gain from this portal is given and consumed both by verified medical professionals , so the portal doesnt filter to support the freedom of speech and research of the doctors, so before you implement it should be your own responsibility to cross check it with you own knowledge and risk before implementation.