I got this to hold a Canon Powershot A570 IS, which is a bit 'chunkier' than the Canon Ixus range. Although the camera went in OK, it wasn't what I would call a perfect fit. Also, the little card pocket on the middle padded orange divider is at the same height as the net pocket on the outer part of the main compartment, so if you put a card in the middle pocket and a couple of AA batteries in the net pocket they lie on top of each other and make the pouch bulge when it is closed.
Throwing caution to the wind, I turned the pouch inside out and cut off the middle divider. The pouch then fitted the A570 like a glove. A spare card fits in the net pocket, and it's just possible to drop a couple of spare AA batteries in the bottom of the main compartment and let the camera sit on top of them (battery compartment/grip down), but it's a tight squeeze and not something I'll be doing.
The 'AW' bit in the name refers to the 'all weather' cover that can be pulled out of a slot between the pouch and the velcro-fastening belt loop (which is itself well thought out and very effective) and stretched over the bag. While I can see the use of this on one of the big Lowepro rucksacks, it seems a bit superfluous on a belt pouch that will be under a jacket anyway if it rains. It also causes a bulge in the pouch when it is tucked away. So the scissors came out again, and the AW cover was snipped off.
After all this I ended up with a somewhat slimmer pouch that is very comfortable to wear on a belt, and holds my A570 as if it was designed for it.
As far as other cameras go, my daughter's Ixus 400 fitted in the unmodified pouch OK together with a spare Li battery and card, but was not quite as snug a fit as the A570. An old A70 (which is bigger than the A570 and takes 4 AA batteries) could just be squeezed into the modified case, but it was quite awkward and not a combination I would recommend.