First off, IBs are not the same as spirit guides or totems. We all have those and they are quintessential on the path.
I walk with two white tigers and have for many many years. They will show up in dreaming. Often they have shown up as cubs. Like this:
I know he looks all cute and cuddly. However even the babies can be dangerous, and when they show up I take good care to not upset them and I tip toe around them greatly.
I was in Nemo's forums and someone at yuku is obsessed with IBs. I wont bring the name here. But my thing is it is not a good idea to consort with them IBs and play around with them, because what their prerogative is, their nature, is to latch on and suck your energy.
They may come across as friends in the beginning, but then later they may invoke feelings of fear, especially if you want them to go. So it is important when they show up to dispatch them on their way.
I dont necessarily believe in brimstone and hell place. But I think there are hellish realms. When they show in dreaming I typically will command them to go back there. I know this does not sound nice, but this is where they reside. They surface up like seaweed and want the light. But their nature is not the light.
Typically IBs are of the lower astral. So like when you play with an Ouija board, this is what comes through. They lie and intimate and say all sorts of things, and typically they will want to get the trust of the human.
As Buddhism says, the human realm is desirable. Therefore they wish to take over and then be like a host in the shell. They can do this. Much ado has been written about possession. if they can succeed, they can take over one's thoughts, to the point where the person is just a shell of their former existence.
So on the path, yes you will encounter them because this path offers a gateway to Spirit. And IBs can come along and serve as a test. It is important to not become infactuated by them and their otherworldly existence. It is important as DJ said, to retain one's sanity. IBs can cause one to lose their sanity. It is playing with the fire to play with them and consort with them.