I don't remember a growth spurt at 4 months. I started TBW program around that time and went from feeding him probably more than he wanted since he was snacking a bit, to stretching him out to a 4 hr routine. He was not asking to be fed more so was fine with 3.5 to 4 hrs between feeds. He was waking up at night and only snacking also, it was at the same time each night so seemed habitual, so I started doing PU/PD instead of feeding and he since has not been fed after the DF until 7 am.
For more than a week now he has been sick so has been feeding more often again, 2.5 to 3.5 hrs between.