I have two 2-year old cats (siblings). They eat canned food only and they eat the same food. The one kitty (who also gets a probiotic) gets periodic diarrhea every 4-6 weeks or so - very loose, very smelly, lasts a couple of days usually. All samples have been negative for all types of bugs and the kitty is otherwise healthy and normal. Have tried to figure out whether it's a protein allergy but that hasn't panned out. We don't know the cause. Anyone have any ideas? Any tips for dealing with the diarrheal episodes themselves in terms of temporary dietary changes or other? Thanks.