What Exactly Does A Hepatology Do?

Hepatologists are medical doctors who manage problems related to liver, gallbladder, bile ducts, and pancreas. 

it doesn't DO anything.

Hepatology is a branch of medicine concerned with the study, prevention, diagnosis and management of diseases that affect the liver, gallbladder, biliary tree and pancreas. 

https://en.m.wikipedia.org/wiki/Hepatology

Hepaology is the branch of medicine that deals with diseases of the liver. Doctors who sub-specializes in hepatology are called hepatologists. They started as residents in internal medicine before going further into their sub-specialization.

Hepatologists are medical doctors who diagnose, treat, and manage problems associated with your liver, gallbladder, bile ducts, and pancreas. Liver problems are a growing issue around the world, with conditions like cirrhosis, fatty liver disease, and hepatitis affecting the lives of millions of people each year.

Nothing.  The correct terminology is hepatologist.

Hepatology is a branch of medicine concerned with the study, prevention, diagnosis and management of diseases that affect the liver, gallbladder, biliary tree and pancreas.

It studies everything bile