That would be pyrosis. Not the nicest thing to have going on in your body. Hope this helps you out.
There are a number of terms that describe heart burn. Acid reflux. Reflux gastritis. Gastric reflux. Chronic heartburn may be indicative of gastroesophageal reflux disease (GERD). Pyrosis may be used, but I will tell you that as a medical secretary, I have never typed or come across the word pyrosis.
That's reflux esophagitis