Pentasa sachets (granules)?

I have not been feeling well lately. I saw my GI coz of a gastritis flare up. He was very reluctant to re -prescribe nexium and zofran iv. When I told him that I can't tolerate pentasa tablets and so have watery d, he decided to put me on iv injections for more 5 days. He suggested suppositories but they have always given me severe cramps. So, he prescribed pentasa sachets or granules 4g. Though I'm taking nexium and zofran iv every 12 hrs, I still have severe gastritis pain. Are these granules better than the tablets? What's your experience?
Any replies will be highly appreciated.