Understanding the role of S100A12 and MPO in the pathogenesis of chronic intestinal inflammation in future and evaluating their use as biomarkers to distinguish between dogs with idiopathic IBD versus healthy dogs or dogs with food-responsive diarrhoea, antimicrobial-responsive diarrhoea and other gastrointestinal diseases may provide the possibility of improving our understanding of canine chronic intestinal inflammation and the current treatment approach. The gene discussed is MPO; the disease is Diarrhea.