Risk factors for IAH-/ACS-inducing acute abdomen among children. Respondents were asked to mention disease patterns which, to their experiences, most often cause IAH/ACS in children (Figure 1). Dependent on the age class, different 'acute abdominal risk factors' were mentioned (n = 32 to 63; percentage of given answers). Dependent on the age causes might be divided into two clusters (neonatal vs. pediatric). FIP, focal intestinal perforation; NEC, necrotizing enterocolitis.