The difference between the internist and the Family Doctor In Columbus lies in the training and depth of knowledge. As an internist explains, an internist is like an adult pediatrician. In short, an internist has extra training and, when all goes well, has more credibility than the family doctor in diagnosis and treatment. These Doctors receive training in psychiatry, internal medicine, obstetrics and gynecology, surgery, pediatrics and geriatrics. After years of experience in the health system over the years, I have concluded that a family doctor has a difficult job.