Diarrhea--would like advice!!

Well, close.....my cat Midnight was on Hills RD to lose weight. Her bowel movements were solid/soft. At the beginning of March she was diagnosed with diabetes and started on Purina DM. I switched her to EVO low carb a month or so later, and several weeks ago found out it was recalled, so I switched her to Raw Instinct. All dry food--I did try wet food but she didn't tolerate it. Ever since her diagnosis, with all 3 foods, her bowel movements have been very loose. Not quite liquid, but close. I clean up 6-12 puddles off my basement floor every day. I have 2 litter boxes that I clean every day but she hasn't pooped in them since our other cat died about 6 years ago. I had her on metamucil for about a month and it didn't make any difference. She does take Fortiflora, which she loves the taste of, but it doesn't make any difference either. They already checked her stool for parasites and it was negative. This has been going on for over 3 months and I just don't think it is healthy for a cat to have such loose bowel movements indefinitely. Before I put her through whatever tests the vet wants to do next week, does anyone else have any other suggestions?? I really don't want her to have to go through surgery or xrays or more bloodwork or whatever they might do. She is drinking a normal amount, eating well, and acting normal. (Regarding the insulin, if you haven't read my previous posts, due to my work schedule and other things that are going on, I usually cannot get a midcycle reading. I just updated the spreadsheet. It kind of seems like 1 unit is too much but 0.75 isn't enough.)

 

Chronic diarrhea causes could include food intolerance/allergy, inflammatory bowel disease, parasites, infection, or cancer.

Have you tried
1) steroids? Yes, the glucose will go up; you adjust the insulin around that.
2) metronidazole? Tastes awful; may help.

To look for food issues:
- Blood test for allergies $$$
- Look at the ingredients for foods fed over the last 6 months. Pick a suspect ingredient - ex protein source or carbohydrate source, and try a diet excluding that for 2 months. Reintroduce the elemnt to see if you observe a change.