I've heard of mastic works for ulcers. I've never tryed it, but have been considering it as I have acid reflux and ulcers as well.
This is taken from the site below.
Recently a study of mastic gum for the treatment of duodenal ulcer, has shown that 70% of the patients were completed healed. futhermore mastic oil has showed remarkable antibacterial activity and a very important fungicidal activity.