running like a zombie

Well hello everyone, I hope all is well. Let me start off by saying I'm not just confused but also very aggrivated by my situation. So I will you in. About 6 years ago I started having horrible stomach pain, numerous trips to the restroom, nausea(with occasional vomiting), and general lethargy. All of this appeared out of nowhere. The doc suggested biopsies, endoscopies and the lovely cup test. Well he found absolutely nothing and ruled it as IBS. Needless to say I was confused and angry that all this was happening. Well fast forward to roday, I have discovered through experimentation that I am lactose intolerant. I tried everything to stop symptoms of this nonsense. I tried medication, didst change and exercise(well you never know haha) but nothing is working. A coworkers suggested I go gluten free and see what happens. Well dive days in and I feel great. Most of my stomach pain is gone, I have made less trips to the bathroom and I'm not really nauseous. So could this be ncgs since I tested negative for celiac?