For some reason on my Inkscape the scroll bar disappeared and I have to navigate using the zoom. It's really annoying, does anyone know how to fix this?

View > Show/Hide > Scrollbars

You probably hit the keyboard shortcut for this (CTRL-B) by mistake. I'm not sure it's something people regularly toggle on-the-fly, or at least not enough to warrant a keyboard shortcut, but it's got one nevertheless.

The scroll bars can be hidden, and you probably did it accidentally. Go to View menu > Show/Hide > Scrollbars and make sure there's a checkmark beside Scrollbars (just click on it). If there is already a checkmark on Scrollbars.....well, I'm not sure. But we can start with you checking on that

Good grief Xav, it appears we've posted simultaneously

And don't forget it's possible to navigate through the canvas by drag'n drop using the mouse wheel.