How many oz is normal consumption for a 5-6 week old?

tinydancingqueen

My little one seems to eat and eat and eat!  Sometimes he eats so fast from the bottle that it all comes up within minutes of him finishing.  Last feeding he ate about 5 oz, in 20 min and it all came back up.  We're resolved to feed him one oz at a time to prevent the excess spitting up, but it takes a long time, especially with the breastflow bottles.  How many oz should a 5-6 week old be eating at each feeding?  I'm just wondering if his appetite is bigger than his stomach.