I.J. Koppen explains the Pediatric Rome IV Criteria, which were established to define and categorize functional gastrointestinal disorders. First established in 1994, the criteria initially only reflected the disorders in adults. In 1999, children were added and in 2006, more specific distinctions were established between adults, neonates/toddlers and children/adolescents. I.J. Koppen goes on to detail the most recent Rome Criteria, published in 2016. He describes the onset and diagnosis of not only the common symptoms but also more rare conditions such as infant rumination syndrome and cyclic vomiting syndrome.