What Is The Treatment For Irregular Bowel Movements And Diarrhea?

Doctor, I have been suffering from Stomach problems since last 1 year. Earlier I was suffering from irregular bowel movements with episodes of diarrhea and cramps. After physical examination and case history, the doctor declared it as IBS-D, I was treated for the same and was asked to add yogurt (Dahi) and avoid milk to my diet. The symptoms were under control but since last few days I am having severe Gas Problem and slight uneasy pain in my stomach mostly near belly button. I also feel sudden cramp and burning sensation at times and there seems urgency to pass stool. I also have a metallic taste in morning after waking up and do not feel like eating anything due to this. In the evenings also the gas problem becomes severe 3 months ago I had a strong stomach pain which was diagnosed to be as a result of gas produced by eating some outside food but the intensity was high hence I got the USG abdomen done to avoid any stone issues. The USG was normal. Kindly suggest I am really confused and not feeling healthy