By that I mean, does he wake screaming, or is it discomfort kind of grunts or just flippity floppity (I believe that's the technical term
)? My little guy kept waking screaming and we finally convinced our naturopathic doctor this was not a normal "phase" of sleeping badly and we determined he was having night terrors (wouldn't recognize us and we had the hardest time comforting him back to sleep, nursing or otherwise). She asked a few more questions and gave him a homeopathic call Stramonium, specifically a constitutional dose (one time big one). We were very skeptical that this could do anything. And miracles of miracles it worked! No more night terrors. I have no idea why, but it did and I don't question success.
We give him a supplemental dose of the homeopathic each night for terrors and teething issues (it never ends does it!) plus an herbal tincture called Melissa Supreme which helps him wind down (lots of energy, this one).
Plus we have to watch the foods he eats during the day (I am finally able to eat cheese again after 19 months, and he can't have dairy himself, or wheat, or corn, or eggs or nuts - or he's fussing at night).
In the meantime, lots of empathy and good thoughts your way. It took until this last month for us to get a few hour block, and now he actually gives us some bigger chunks and all I can say is maybe it's because we do all the above, plus he's older. I know, when my doctor said it would be over someday and he would outgrow some of the night stuff it was no consolation either - the thought of future sleep does absolutely nothing to help your deprivation at the time.
Keep trying and consult your doctor, especially if you can see a naturopathic one; there are herbal and homeopathic things (different ones to fit each child) to try and possible food sensitivities they can help you steer through.