What is the difference between a family practice doctor and an internal medicine doctor?

The first answer is totally wrong. Once you get out of medical school, you can specialize in many different things. 2 of them are internal medicine and family practice. Not all doctors have a "degree" in internal medicine.

Internal medicine is an adult-centered specialty, which concentrates on an understanding of how the body works as a whole and all of the physiologic processes that go on inside it. A general internist can work in either a hospital or community setting and treats many common diseases such as diabetes, hypertension, pain, etc, and refers to others as needed.

A family practice doctor is trained in pediatric and adult medicine. They are more well versed in general care of all ages and sexes. Family practice docs are often more community based, but there are many that work in hospitals too. A family practice doctor is more qualified to be a "jack-of-all-trades", doing general gynecologic, medical , and minor surgical needs, which makes them ideal for a rural doctor where there are few other docs around.

The short answer is, you’ll be fine going to the family practice doctor for your pain. An internal med or family practice doc will know when to refer you if necessary. Good luck!

All doctors have either an MD (medical doctor) or OD (doctor of osteopathy. The difference between a family practitioner and an internist is the residency they have completed.
Internists diagnose and treat medical disorders of the adult patient’s internal organs; heart (hypertension and high cholesterol), liver, kidneys, pancreas (diabetes), lungs, and gall bladder. They will also refer to surgeons of all kinds and other medical specialties.
A family practitioner’s emphasis is on preventative medicine within the context of the family. They have extra training in obstetrics, pediatrics, and geriatrics, which most internists don’t. They are trained to refer patients to specialists for problems which are complicated and actually send patients to an internist if the patient has multiple medical problems.