In my experience the only thing that has massively lessened Matthew's reflux is time. Cutting out dairy/soya improved him immensely in terms of tummy pain, horrid poos, poor weight gain and general irritability. It did decrease the reflux (probably because the gut probs made him reflux more?) but he still refluxed significantly well into his second year. I'm fairly sure he is not intolerant to anything else.
I don't know about the omeprazole - we did both things around the same time and Matthew was on the omep for a year. I wonder now if he needed it or if the diet changes alone would have been enough - at the time I was so desperate for things to improve I wanted everything done. On the other hand, I think the meds will not work well if there is an untreated intolerance so I'm not surprised when you last tried it you didn't get good results.
If he tolerated the omep and you are left with reflux that is significant adversely affecting him I think I'd give the meds another try. Or alternatively, would you feel you can carry on as you are until he's 18m/2yrs....?
We were initially given ranitidine then omperazole too when my LO was very young and like yourself found it made no difference. The screaming, lack of sleep and refusing to feed still continued.
The switch to nutramigen and then neocate made a big difference for us along with introducing only low allergen foods and doing so gradually. He started putting on the weight but I'm afraid the sleeping was still terrible. For us this didn't improve properly until we were put back on to Omeprazole. I had to play around to get the best dosage for him (enough to be comfortable but not more than was necessary). Seb now sleeps through the night and just the last week has started sleeping for 12 hours at a time. I think part of it is age as he's now 15 months but the way in which the drugs have been introduced (i.e.not together) show me that for us the omeprazole was a big part of the puzzle and has definitely helped to make him more comfortable.
Hope this makes sense and helps you with your decision.x
Jenny, have you tried thickening the neocate feeds? Certainly with Harry he refluxes a lot more if his feeds aren't thickened, but not sure if the same applies to a silent refluxer rather than a puker. You might have to be careful with what you use to thicken though. We were initially prescribed carobel but he was horrible on it (I think carob seed this is made from is related to soya). Then we used thick and easy (corn based) which was great re the reflux but gave him awful diahrrea. Now we use baby rice on the recommendation of the dietitian.