My children become severely constipated when they turn 3 but before that age they ok and they even go three to two times a day. Now my child DS3 goes every three days and it’s huge and hard. It’s same pattern with my eldest which he ended up impacted etc and on movicol till now. What’s the cause why when they turn 3. Diet still the same lot of water fruit and vaggie. They even like lettuce and spinach so not fussy eater at all. As soon they turn three something switch. They go from regular to every 3 days and bloody huge.