Works TOO well against diarrhoea
One of my Maine Coons has very sensitive intestines, with a history of both extremes: from constipation to diarrhoea and back again. In our experience, Hill's Biome works well in cases of diarrhoea, but if there's constipation, it's better to go for Royal Canin Fibre. Feeding just one type of food always caused problems for us, so now we give a mix of both and that's working well for now.