Urea breath test is done in:
The urea breath test is a rapid diagnostic procedure used to identify infections by Helicobacter pylori, a spiral bacterium implicated in gastritis, gastric ulcer, and peptic ulcer disease. 
It is based upon the ability of H. pylori to convert urea to ammonia and carbon dioxide.
Ketoacidosis
H. pylori infection
Kidney disease
Liver disease