My 10 week old baby can’t keep her formula down.  I’m not a first time mom and I understand babies spit up, but this is throwing up.  I have tried several different formulas, Zantac, feeding her sitting straight up, and burping her after every ounce.  Her doctor keeps saying she has a premature esophagus, but she wasn’t premature, and the formula seems to be staying down too long for it to be that.  She is putting on weight because sometimes it will be an hour or more after eating that it all comes up.  She cries all the time and wants to eat constantly; it seems to interrupt her naps during the day too.  It has gotten to the point where I will feed her an ounce or so without burping just to calm her stomach, and then wait for her to throw it up.  The doctor said she should grow out this by about 4 months but it’s getting worse.  We are afraid to let anybody hold her because she will throw up.  Can you give me any advice?  Could there be something more wrong with her?