Why would my son's eating pattern change?

My son is 5 months old. About a month ago, at our peds advisement, we moved him out of our room and into his own room. He was doing very well with sleeping in his own room. He slept better and longer than he did in our room. The ped also wanted us to gradually start reducing the amount (ounces) he ate at night. He was doing great--only waking once a night to eat and sometimes not waking up until morning. Lately(the last week or so), he has been waking up every 2-3 hours to eat. I tried to continue with his 3 oz bottles during the night feedings but he would awake again 30 minutes to an hour later-STARVING. Last night he woke up 3 times from when I put him down at 8:40pm to when he woke up for good at 6:30am. He ate a full 5 ozs all three times. Could he be going through a growth spurt? Has anyone else experienced this with their baby?