What Causes Excessive Gas Around Liver?

I have used zantac off and on for 7-8 years. Usually one when needed. Recently over the last month I was having to take 2-3 per day to get some relief. I started using Prilosec along with the zantac. I still get a very uncomfortable feeling in my upper abdomen (feels like someone has a belt tied around me under my breast) My dr. started me on Dexilant about 3 days ago. It has made me feel a lot better. I had an abdominal ultrasound today. The technician said I had a lot of gas around my liver? What is that caused from?