If you have diarrhea, you can first see your family doctor or a general practitioner and may be referred immediately to a digestive or gastrointestinal specialist. When you set up your appointment, ask if there's anything you need to do in advance, such as restrict your diet. For example, you might drink lots of clear fluids - to help avoid dehydration - and avoid fatty, high-fiber or highly seasoned foods.

Office visits can be brief and there's a lot of ground to cover. So it's a good idea to be prepared for your appointment. Start by making a list of symptoms you're experiencing as well as major stresses, recent life changes or travel. Also make a list of all medications you currently take, as well as any vitamins or supplements.

Medical exams
During an office visit, your doctor will first review your medical history and perform a physical examination. Your doctor will probably ask about your symptoms and will want to determine if you're dehydrated. The doctor will ask you about your eating habits and medication use and will examine you for signs of illness.

Your doctor may examine your abdomen to determine the location of your pain and listen to your abdomen with a stethoscope. Additionally, s/he may perform a digital rectal exam. Your doctor may suggest blood or stool tests to check for signs of infection or other abnormalities. Diagnostic tests used to find the cause of diarrhea may include the following:

• Blood tests - Blood tests can rule out certain diseases

• Colonoscopy - This test allows the doctor to view the entire colon.

• Fasting tests - Fasting tests are used to find out if a food intolerance or allergy is causing diarrhea. The doctor may ask you to avoid lactose, carbohydrates, wheat, or other foods to observe whether or not diarrhea responds to a change in diet.

• Imaging tests - Imaging tests can rule out structural abnormalities as the cause of diarrhea.

• Stool culture - A sample of stool is analyzed in a laboratory to check for bacteria, parasites, or other signs of disease and infection.

• Sigmoidoscopy - During this test, the doctor uses a special instrument to look at the inside of the rectum and lower part of the colon.

A few cases of diarrhea can be diagnosed after brief medical history and physical examination. Some cases will require further examinations. But how do doctors treat diarrhea? To learn more about treatments for diarrhea, read the Diarrhea Treatment section that follows.