doctor in cytology
A doctor who specializes in the digestive tract is a gastroenterologist.
Gynecologist
I think you mean a gynaecologist - a doctor that specializes in women's health, especially the female reproductive system.
A doctor that specialises in children is called a paediatrician. The doctor who specializes in diabetes is a nephrologist.
Electrophysiology Cardiologist.
A doctor who specializes in heart problems is called a cardiologist.
A doctor who specializes in the colon, rectum, and anus is called a proctologist.
A Doctor who specialises in Ano rectal diseases is called a Proctologist.
A doctor who has specialised in blood called a Hematologist.
A doctor who specializes in pregnancy is called an obstetrician.
A doctor who specializes in the care of animals is called a Veterinarian.
A Pediatrician.