The bails must be dislodged for a batsman to be out bowled
As a batsman, it is your duty to protect the stumps.
But if a bowler manages to get a ball through and knock off the bails, the two bits of wood resting at the top of the stumps, then the batsman is out "bowled".
A batsman is still out bowled if they accidentally deflect the ball onto the stumps off their bat or pad.
But you cannot be bowled off a no-ball.