Had Murphy eating I'm afraid
@Ashley. Murphy lived to the grand old age of 15. To begin with he was on Royal Canin veterinary diet sensitivity control which at the time was white bait and tapioca. It has now changed to duck and tapioca. The main point of the ingredients though is that they are rarely associated with food intolerances.
Sensitivity Control SC 21 - Dog Food - ROYAL CANIN® and is recommended for colitis and sensitive digestion. Are you in Australia Ashley ? I'm only guessing because your vet suggested kangaroo. If so this might be more useful
https://www.royalcanin.com.au/products/products/vet-products/vet-diet-canine/sensitivity-control The vet also recommended putting him on a pro/prebiotic supplement. I used Protexin bio premium which murphy loved and for a lab he was a fussy eater. It's a powder you just sprinkle over their food.
Bio-Premium for dogs - Protexin Although Murphy didn't go through the horrific ordeal you and Quinn have been through he did have regular bouts of colitis, mucus/bloody diarrhoea, meaning regular antibiotics and anti inflammatories. Once I'd sorted out his diet he improved so much he hardly had diarrhoea again it was quite remarkable. Diet might not work as effectively for Quinn because of the trauma her guts have been through but as she's been diagnosed with inflammatory bowel disease I do think it will help a lot and I'm sure over time her bowels will calm down from what they've been through and hopefully the diet will work as well for Quinn as it did for Murphy. If you can't get the Royal Canin I would recommend a food containing white fish and no other protein. White fish is easily digested and not too rich murphy couldn't cope with salmon for example. Once you've found a diet that she likes and suits her stick with it. That also includes treats. Try and get treats with the same protein as the food for example dried fish skin. I do hope you can get Quinn's tummy settled and then maybe you can settle a bit too. I can imagine your probably still on edge and worrying.