Gastritis is inflammation of the gastric mucosa caused by any of several conditions, including infection (Helicobacter pylori), drugs (NSAIDs, alcohol), stress, and autoimmune phenomena (atrophic gastritis). Many cases are asymptomatic, but dyspepsia and GI bleeding sometimes occur. Diagnosis is by endoscopy.
A gynecologist is a doctor who specializes in women's reproductive health. Obstetricians care for women during their pregnancy and just after the baby is born. They also deliver babies. An ob-gyn is trained to do all of these things. Your ob-gyn will deal with some of the most important health issues in your life, including birth control, childbirth, and menopause. An ob-gyn can also screen for cancer, treat infections, and perform surgery for pelvic organ or urinary tract problems.
OB/GYN is the abbreviation for an obstetrician-gynecologist. An OB/GYN has many jobs. What you see an OB/GYN for depends on where you are in your life. For the majority of your life, you will need the services of a gynecologist. An obstetrician's services are only needed when you are pregnant. Some doctors are both obstetrician-gynecologists.