Question: How do doctors find the cause of constipation?
Answer: Doctors use your medical and family history, a physical exam, or medical tests to diagnose and find the cause of your constipation.

Medical and family history

Your doctor will ask you questions about your medical history, such as

whether you have ever had surgery to yourdigestive tract
if you have recently lost or gained weight
if you have a history ofanemia

Your doctor also is likely to ask questions about your symptoms, such as

How often do you have abowel movement?
How long have you had symptoms?
What do yourstoolslook like?
Do your stools have red streaks in them?
Are there streaks of blood on your toilet paper when you wipe?

Your doctor is likely to ask questions about your routines, such as

What are your eating habits?
What is your level of physical activity?
What medicines, includingsupplements, and complementary and alternative medicines, do you take?

You may want to track your bowel movements and what your stools look like for several days or weeks before your doctor’s visit. Write down or record the information so you can share it with your doctor.

If you’ve been constipated a long time, your health care professional may ask whether anyone in your family has a history of conditions that may cause long-lasting constipation, such as

anatomic problems of the digestive tract
intestinal obstruction
diverticular disease
colon or rectal cancer

Physical exam

During a physical exam, a health care professional may

check yourblood pressure, temperature, and heart rate
check fordehydration
use a stethoscope to listen to sounds in yourabdomen
check your abdomen forswellingtenderness or painmasses, or lumps
swelling
tenderness or pain
masses, or lumps
perform arectal exam
Question: What medical tests do doctors use to find the cause of constipation?
Answer: Depending on your symptoms and health, your doctor may first try a treatment to improve your symptoms before using tests.

Lab tests

Your doctor may use one or more of the following lab tests to look for signs of certain diseases and conditions that may be causing your constipation

Blood testscan show signs of anemia,hypothyroidism, andceliac disease.
Stool testscan show the presence of blood and signs of infection and inflammation.
Urine testscan show signs of diseases such asdiabetes.

Endoscopy

Your doctor may perform an endoscopy to look inside your anus, rectum, and colon for signs of problems in your lower digestive tract. Endoscopies for constipation include

colonoscopy
flexible sigmoidoscopy

During these two tests, your doctor may also perform a biopsy. A biopsy is a procedure that involves taking small pieces of tissue and examining them under a microscope. A doctor can use a biopsy to look for signs of cancer or other problems.

Colorectal transit studies

Your doctor may use bowel function tests called colorectal transit studies to see how well your stool moves through your colon.

Radiopaque markers—anx-raythat tracks radioactive markers while they pass through yourdigestive system. You swallow capsules with the markers, which take about 3 to 7 days to come out with a bowel movement.
Scintigraphy—a test that involves eating a meal with a small dose of a radioactive substance. Your doctor tracks the substance using special computers and cameras as the substance passes through yourintestines.

Other bowel function tests

Your doctor may also use one or more of the following tests to look for signs of certain diseases and conditions that may be causing your constipation

defecography—an x-ray of the area around theanusandrectumto see how well you can hold and release stool
anorectal manometry—a test to check how sensitive your rectum is, how well it works, and how well the analsphincterswork
balloon expulsion test—a test that involves pushing a small water balloon from your rectum to see if you have a problem pushing out stool

Imaging tests

To look for other problems that may be causing your constipation, your doctor may perform an imaging test such as

lower gastrointestinal (GI) series
magnetic resonance imaging
computed tomography (CT) scan