Painful affliction (5)
(Other definitions for ulcer that I've seen before include "Cruel kind of open sore" , "Cruel form of stomach trouble?" , "cause of suffering" , "Inflamed lesion" , "Cruel kind of bodily sore" .)
'painful affliction' is the definition.
This is the entire clue.
(Other definitions for gout that I've seen before include "Swelling disease" , "Disease caused by excess uric acid in the bloodstream" , "Toe-swelling disease" , "Painful ailment, often of the foot" , "Toe-inflammation disease" .)
(Other definitions for heartburn that I've seen before include "Painful sensation" , "minor ailment" , "Hot sensation in lower chest from indigestion" , "Acidic reflux" , "Chest pain" .)