My son fell and is now complaining of pain in his foot. there is no bruising or swelling anywhere. it happened 12 hours ago. how can i help?

X ray : To be sure, take him to your pediatrician or peds ortho for an xray. There does not have to be an obvious deformity for a fracture to occur.

Ice: You don't say how old he is. Ice on and off is always a good idea for a sprain. Elevate, keep off foot and if necessary see a podiatrist and get an x-ray. Ibuprophen or naprosyn (naproxen) otc if he can tolerate it and has no allergies to these meds.