Quoting Erin Berlin:" Unless you consider 5 oz at a time to be small, then no. Before bed and when he wakes up in the morning ... [snip!] ... don't let his feet touch our laps. He also like to be lightly bounced in that position. As for spitting up often, definitely."
id say reflux then.
try elevating the top end of his bassinet, a paci, sitting up as much as possible for feedings and for about 20 mins after feedings, maybe even try infant gaviscon, unfortunatly none of this worked so the doc told me to put him on a couple of spoonfuls of rice cereal a day, didnt work either finally at 5 months old he started his meds, worked wonders!