Severe gas with terrible smell. To take.

I have been facing gastric tissue since very young age. In the year 2017, I visited one gastroenterologist and he did colonoscopy and gave few medicines, I continued it and everything was fine. He asked me for some restrictions also such as raw onion, cucumber, cabbage, milk, fried food, butter, ghee. I'm a vegetarian. I drink alcohol not very frequently. Yu can say 2-3 times in a month that too in moderate amount. But since last year Nov'2018 when I visited my hometown I had few meals with oily food that was road side. And since then my old problem is started again. Now since last one month I am following strict diet with very minimum oil and no outside food. Still the gas issue is not resolved. The problem is the smell, it's too embarrassing. Please help, I can share you more details and some reports and medicines I used to take. Thanks for your anticipated cooperation.