What Causes Itchy Skin On Anal Area?

28, 140 lbs. No health issues.... but I have an itchy bottom/crack. I think I may have a small external hemorrhoid, but it seems to disappear when I am not feeling itchy down there. Is this normal? Could I be raw/itchy due to over wiping? I feel pressure in the anal area when standing too long or holding my 2 year old too much. I've had softish stools. Could it be worms?