If your doctor suspects you may have diverticulosis or diverticulitis, your doctor may use your medical history, a physical exam, and tests to diagnose these conditions. Doctors may also diagnose diverticulosis if they notice pouches in the colon wall while performing tests, such as routine x-rays or colonoscopy, for other reasons.

1. Medical History
Your doctor will ask about your medical history, including your bowel movement patterns, diet, health, medicines, symptoms.

2. Physical Exam
Your doctor will perform a physical exam, which may include a digital rectal exam. During a digital rectal exam, your doctor will have you bend over a table or lie on your side while holding your knees close to your chest. After putting on a glove, the doctor will slide a lubricated finger into your anus to check for pain, bleeding, hemorrhoids, or other problems.

3. Blood test
A health care professional may take a blood sample from you and send the sample to a lab to test for inflammation or anemia.

4. CT scan
A computerized tomography (CT) scan uses a combination of x-rays and computer technology to create images of your gastrointestinal (GI) tract. An x-ray technician performs the procedure in an outpatient center or a hospital. A radiologist reads and reports on the images. You don’t need anesthesia for this procedure.

For a CT scan, a health care professional may give you a solution to drink and an injection of a special dye, called contrast medium. Contrast medium makes the structures inside your body easier to see during the procedure. You’ll lie on a table that slides into a tunnel-shaped device that takes the x-rays. A CT scan of your colon is the most common test doctors use to diagnose diverticulosis and diverticulitis.

5. Lower GI series
A lower GI series, also called a barium enema, is a procedure in which a doctor uses x-rays and a chalky liquid called barium to view your large intestine. The barium will make your large intestine more visible on an x-ray.
An x-ray technician and a radiologist perform a lower GI series at a hospital or an outpatient center. A health care professional will give you written bowel prep instructions to follow at home before the procedure. You don’t need anesthesia for this procedure.

For the procedure, you’ll be asked to lie on a table while the radiologist inserts a flexible tube into your anus and fills your large intestine with barium. You will need to hold still in various positions while the radiologist and technician take x-ray images and possibly an x-ray video, called fluoroscopy. If pouches are present in your colon, they will appear on the x-ray.

6. Colonoscopy
Colonoscopy is a procedure in which a doctor uses a long, flexible, narrow tube with a light and tiny camera on one end, called a colonoscope or endoscope, to look inside your rectum and colon. A trained specialist performs a colonoscopy in a hospital or an outpatient center. A health care professional will give you written bowel prep instructions to follow at home before the procedure. You will receive sedatives, anesthesia, or pain medicine during the procedure.

During a colonoscopy, you’ll be asked to lie on a table while the doctor inserts a colonoscope into your anus and slowly guides it through your rectum and into your colon. Doctors may use colonoscopy to confirm a diagnosis of diverticulosis or diverticulitis and rule out other conditions, such as cancer.