Hi Beccy,
Just to echo Annemarie's experience. My girl, Tilly had a very nasty bout of colitis when she was a small puppy. She had an injection and some medicine from the vet and recovered within a few days. She was back on her normal food within a week. I was told that she may be more susceptible to colitis in the future, but so far we have not had another bout (Thank God!). Tilly frequently tests her digestive capabilities through her favourite snack of cow and sheep poo but she comes through the test pretty well! This pretty girl with the disgusting secret eating habits is now 14 months old (not so secret now, eh, Tills? :wink: ).
I know how scary it can be when they are poorly, particularly when they are small. I do hope that Twix recovers quickly and is with you soon.
Sue and Tilly