“…Environmental, behavioural, immunological and genetic factors may contribute to functional constipation [ 9 , 12 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. The typical mechanism is behavioural stool withholding because of pain, inflammation or anal fissure, which can lead to a vicious cycle of large, firm, painful stools and further withholding [ 12 , 18 , 19 , 20 , 21 , 22 ]. Children with autism, neurological or motor disorders, developmental, psychiatric and behavioural conditions, atopy and food allergies and children exposed to abuse, violence or psychological stress are more prone to develop constipation [ 18 , 19 , 20 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ,…”