Hi There. I Have Been Having Gastrointestinal Problem For More

Hi there. I have been having gastrointestinal problem for more than three years. My Coeliac Profile was also normal. I avoid all gas causing foods such as Rice, Potatoes, Lentils, Beans, Legumes, Cauliflower etc, which may cause a minor gastric problem, yet no relief. Please guide me what should I do to get relief because its really very difficult to live with a persistent gas in the abdomen.
Thanks