Your doctor will ask about your symptoms and about the appearance of your bowel movements. He or she will ask if you have recently traveled to developing countries, been in contact with people who have severe diarrhea, or might have been exposed to contaminated pools, lakes or food.
Your doctor will diagnose shigellosis based on a physical examination and the results of laboratory tests. These tests include taking a swab of your rectum or a sample of your stool (feces). If you have signs of dehydration (excessive loss of body water) or significant blood loss, additional blood tests may be necessary.