According to a report on Chinese television, as translated by Rocket News 24, 'professional fart smellers' in China are being paid upwards of 300,000 yuan a year.
These professional hyperosmiacs smell their patients' farts and diagnose their physical health based on the odour. By "picking up on traces of sweet, savoury, bitter and even meaty aromas" the olfactory experts allege that they can identify illnesses and pinpoint their location in the body (which, by the way, doctors can do as well).
Extremely bad smelling flatulence can indicate bacterial infection in the patient's bowels or intestines.
The group also claims to be able to tell a lot about a person's physical wellbeing by measuring the amount of gas expelled with each fart, with enormous guffs suggesting that we're consuming too much fibre and mere whispers hinting at intestinal obstruction.
We're not sure whether one should be impressed or appalled that these shysters have convinced people to pay them good money for telling people something they should already know (that if you have very bad smelling, recurrent flatulence you probably have a stomach upset).
Because a quack career path wouldn't be complete without arbitrary hurdles to prevent too many people getting in on the con, the 'industry' requires that applicants must be aged 18-45, completely abstain from cigarettes and alcohol and be free of any kind of nasal impairment or related illness. There's also a number of tests and an elaborate training course (which you presumably have to pay for) before you will be qualified to sniff someone's behind and confirm that it smells before taking their money and sending them to a real doctor.