I have been bulimic for 4 years. After the last purge, I got extremely painful heartburn. I had stomach acid pooling in mouth. Is it just heartburn or something more?

No. As you know, the cure/treatment isn't about treatment of one symptom only to have this recur or worsen. Please consider seeking a caring health care provider. Http://www. M.webmd. Com/a-to-z-guides/tc/bulimia-nervosa-treatment-overview.
Could be more. If you've been bulimic for 4 years, you can damage your stomach and esophagus along with many other things. It's possible that this last bout of purging did this, leading to "extremely painful heartburn" feeling. I encourage you to please see a physician and get the help you need. Your health and welfare matter.