I have a 5 week who is colicky in the evenings. He nurses well all day but in the evening he fitfully nurses on and off for a few min and then comes off the breast screaming. I feel it is because of forceful letdown because sometimes he coughs and chokes. Although he seems to handle that force during the he just wont nurse in the evening. I have tried pumping before nursing, I hold him higher than the breast but nothing works. Is it colic that is causing the problem or my letdown?