Surbhi and namit lived as sid and Ishani for almost 115 episodes. And we have seen how both cared and cried for each other . How sid took care of Ishani during coma and how Ishani supported sid through out his struggle. So one fine day this new Navarathna guy comes and we all should accept them like that . I really can't do that .audience watch a show to know when their lead couple will meet again and unite . So here they kept sid 's case as mystery. Definitely he didn't go to USA . Something unfortunate happened with him .so from my opinion any show work on the basis of couple not for one character.