MPO and inflammatory bowel disease: Recent work demonstrated that fMPO is an accurate biomarker of endoscopic inflammation in adults with IBD, with elevated levels predicting a more complicated disease course.17,18 Serum MPO levels have also been shown to be elevated in children with IBD (n = 35) compared to controls (n = 32).19 However, to the best of our knowledge, there have been no studies assessing fMPO as a marker of inflammation in children with CD.