Cat trouble...

Just brought our new cat home from sanctuary 3 days ago, and she has started to occasionally go through 'attacks' where she thrusts her head forward as if hiccuping or sneezing, and it sounds as if there's some kind of furball trapped in her throat or something.

Have fed her pouched food (which is a different flavour to the one that she got at the sanctuary, but the same brand), and realise that this can give cats diarrhoea problems, which has happened also, but is going slowly.

Any suggestions about what this could be?

We're not very experienced with pets, as this is our first cat, so please help us out! We feel terrible!

It could well be a furball...they make those sort of sounds and head thrusts with them. Mine does it quite often. Guess it's all the cleaning themselves that they do.
Just keep an eye on her to make sure.