Hi Steph,
I've not come across any studies to support this impression but since I became a member here over 2 years ago, I have observed anecdotally that some cats may experience digestive upsets shortly after commencement of treatment. One possible reason might be that a diet change took place but I also do get the impression that some GI upsets may be due to the body getting used to the 'foreign' insulin. Again just based on what I've observed here it seems to typically be a transient issue but it is wise to monitor the cat closely and get the vet to check it over. Note that other members may not have similar thoughts.
Have you changed Chuck Norris' food since diagnosis? That might be a possible cause.
To be on the safe side, I suggest getting your vet to give Chuck a once-over and that you ask for a pancreatitis blood test; pancreatitis can make poo
extremely malodorous. If your vet offers SNAP fPL testing in-house it will give an immediate yes/no result. The Spec fPL test needs to be sent out to the external lab but they give a numeric result indicative of the level of severity of any inflammation present. With IBD in the mix getting B12/folate tests done is wise (nutrient malabsorption being a common issue with this condition, as I'm sure you already know). A full panel with thyroid and lipids, etc., is valuable. Should blood tests indicate pancreatic inflammation is present an ultrasound scan may give you additional diagnostic information.
Watch for changes to the colour and texture of the poop. If it gets paler/grey-looking, marshmallowy/'fluffy-looking' (steatorrhoea), or turns to diarrhoea this could also point to issues with the pancreas (both problems are due to lack of pancreatic enzymes so food passes through the gut without being properly digested or absorbed).
Keep an eye out for any nausea / inappetence symptoms or different signs of abdominal discomfort (e.g. crouching in a tense meatloaf position after eating; seeking out cool floor surfaces to sit/lie on; tenderness on palpation).
Here are some useful links for you in case you might need them:
Nausea and inappetence - symptoms and treatments
IDEXX Pancreatitis Treatment Guidelines
IBD Kitties home page
IBD Kitties B12 info
Mogs
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