Your doctor can order no tests or many types of tests and procedures. The decision of which ones your doctor might order for you depends on your symptoms, medical history, and overall health.
Lab tests: Blood and urine tests reveal signs of hypothyroidism, anemia, and diabetes. A stool sample checks for signs of infection, inflammation, and cancer.
Imaging tests: Computed tomography (CT), magnetic resonance imaging (MRI) or lower gastrointestinal tract series may be ordered to identify other problems that could be causing your constipation.
Colonoscopy: A colonoscopy or sigmoidoscopy– an internal view of your colon with a scope – may be performed. During this procedure, a small sample of tissue (biopsy) may be taken to test for cancer or other problems and any found polyps will be removed.
Colorectal transit studies: These tests involve consuming a small dose of a radioactive substance, either in pill form or in a meal, and then tracking both the amount of time and how the substance moves through your intestines.
Other bowel function tests: Your doctor may order tests that check how well your anus and rectum hold and release stool. These tests include a certain type of x-ray (defecography), done to rule out causes of outlet dysfunction constipation, and the insertion of a small balloon into the rectum (balloon expulsion test and anorectal manometry).