When you feel the urge to poop you really should get to the toilet as soon as possible and poop so that you don't cause any problems with your bowels and health.
Holding your poop in too long could lead to bowel blockage or constipation.
The longer your poop is held in the rectum the more water is absorbed from it which then leads to your poop being harder and then it gets more difficult to pass.
So you could cause constipation or bowel blockage from holding your poop in too long.
Also your poop contains bacteria that is not healthy to stay in your colon and intestines and you need to get rid of that bacteria filled poop to prevent illness.
So only hold your poop for as long as you need too and get to the bathroom as soon as possible and let the poop out so you prevent constipation or prevent any potential illness from the poop being held in.