Diagnosis of Constipation
How do doctors find the cause of constipation?
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 your digestive tract
- if you have recently lost or gained weight
- if you have a history of anemia
Your doctor also is likely to ask questions about your symptoms, such as
- How often do you have a bowel movement?
- How long have you had symptoms?
- What do your stools look 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, including supplements, 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 your blood pressure, temperature, and heart rate
- check for dehydration
- use a stethoscope to listen to sounds in your abdomen
- check your abdomen for
- swelling
- tenderness or pain
- masses, or lumps
- perform a rectal exam
What medical tests do doctors use to find the cause of constipation?
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 tests can show signs of anemia, hypothyroidism, and celiac disease.
- Stool tests can show the presence of blood and signs of infection and inflammation.
- Urine tests can show signs of diseases such as diabetes.
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
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—an x-ray that tracks radioactive markers while they pass through your digestive 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 your intestines.
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 the anus and rectum to 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 anal sphincters work
- 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
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK), part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.