sounds like reflux to me. My gal had reflux AND colic so i can tell the diff. Colic for her didnt end at 3month, it peaked when she was about 3mths++ going on 4mths. And she really did jus cry and cry for 3hours, started right on the dot at 5pm up till 8pm (when she slept out of sheer tiredness, i think). Reflux, she will be arching her back in pain, regardless of the time of the day, and will calm down when held upright.