Taken various prescriptions but nothing works

I have a stomach problem for last five years. I had 3 Colonoscopies, one Endoscopy, two kidney ultrasound and one CAT scan of the whole abdomen. However; the doctor did not find anything. I wake up around 3:00 a.m. every night with mild discomfort on the upper right hand side of my abdomen. I feel bloated and full of gas. I take water with Apple Cider Vinegar and baking soda. After 1/2 an hour I go back to sleep. It happens almost every night. I also have frequent urination during the night (4-5 times). I also get left shoulder pain and ringing in my ears. Some day all this goes away for a couple of day but then comes back. It is disturbing my sleep and I feel tired during the day. My all blood tests are normal. Sugar and cholesterol are within normal range. I am lactose in tolerant. I am allergic to eggs.

I think either I am allergic to something in my diet or have some stomach problem that doctors cannot figure it out. I am little heavy but walk an average of couple of miles per day. I have a good professional job and am active.

I have taken various prescriptions but nothing works. I am not taking anything at this moment. Has anyone had a similar experience or have any suggestion what should I do. I go to doctors but they don't take serious and give strong prescriptions that have more side effects which make my situation worse.

I would like welcome comments and suggestions from the readers on this website.

Moderator: Did I say any where night walking in my post?

yes, he did take a sample of the tissue and it was negative. He also done a blood test to determine if I have
Celiac disease but it turned out negative too.

One of my friend just mentioned that he had the same problem and doctor gave told him it might be some stomach ulcer. I have been drinking cabbage juice for the last three days to cure ulcer and it is making hell
of a difference. I am sleeping well and discomfort is subsidizing. I have also read DGL (Licorice) is good for ulcer. I have just started this evening. I will keep this forum posted on a weekly basis.

Thanks every one for their responses.

Note: I make cabbage juice at home with Red cabbage and don't mix any thing with it. I take 8 oz glass three times a day.

Thanks for your response. How can I find hidden lactose? What type of ingredient I am looking for? Any suggestion.Our food is full of ingredients that are harmful to our body. However; to hide the evils the manufacturers have developed very sophisticated names for the ingredients that it is difficult to understand for a common person. Any suggestion or guidance would be helpful.

Thank you.