If you don't return to breastfeeding, keep a detailed log of what your child is taking in ml's and the time they took it. You can find patterns for the reflux and see exactly how "downhill" the feedings are going. I started this with my son when he was one month old, before he was diagnosed with reflux.
Unfortuantly, if his weight gain gets to bad or he loses weight they will want to place an n/g tube for tube feedings, that is where we are right now. If he does start to loose weight they will albel him failure to thrive and will ask you to put a tube in place.
With that all said refluxers do ALOT better on breastmilk than formula. Try to start back at it even if you pump for him while you are at work. My son had such a hard time nursing/eating in general because he had a heart defect I was going to kill myself from lack of sleep if I had kept pumping.
Reflux meds. can be given to children as well, our son had been on MANY. A word about meds. you have to keep trying until you find the one that works for your child. It can get expensive. It cost us a minor fortune.
Whatever you do don't try to force him to eat. We were told our son's feeding was all behavioural (before we knew it was reflux) and were told how to kind of force him to eat by therapist and it made his aversion to the bottle horrible. At 3 months he wa kicking and screaming at the sight of his bottle. Because he was in pain.
If he is arching his back at feeds and moving his head from side to side as you give him the bottle, he is in PAIN, don't force it. Some children will take a few oz. before they start to reflux and then the pain of reflux will stop them from eating any more, hence, the less weight gain and sometimes weight lose.
Hope this helps, we have been through the ringer with reflux. Some parents have had it much worse than we have. You can get alot more info at www.parent-2-paretn.com it is a support web site for refluxers. (gerdlings they are called. GERD gastrointestinal reflux disease, I think I spelled it right. I will want you the p-2-p website can be overwhelming and graphic sometimes, but it can help alot.