Stomach bloating and pressure

Abdominal bloating for 1–2 weeks is usually due to a diet or eating habits, but, abdominal bloating with abdominal pain for longer period needs medical attention.
It is a main complain along with abdominal pain and changed form and frequency of bowel movements, in condition known as irritable bowel syndrome.
Also, you may have lactose intolerance, not having enough lactase to digest the amount of lactose in milk products.
Symptoms begin about 30 minutes to 2 hours after eating or drinking foods containing lactose, like nausea, cramps, bloating, gas, and diarrhea.
Some foods causes larger amounts of gas to be produced when the food is digested.
Eat smaller meals slowly, cause fast eating leads to swallowing air that gives the feeling of abdominal bloating.

My husband started getting this same condition in March and he still has it. He had an endoscopy and colonoscopy already - came out normal. He is miserable every day and no one seems to know what is the reason or how to relieved this condition.