Diagnosing IBS With A Physical Exam
In addition to taking a patient’s symptom history and running laboratory tests, physicians use a physical exam to diagnose irritable bowel syndrome (IBS). The physical exam is often normal in IBS cases because there are usually no physical signs to definitively diagnose IBS.1,2 IBS is called an invisible illness since most of the time patients appear fine on the outside.
The physical exam for diagnosing IBS is used, in part, to rule out other conditions. For example, physicians will note the presence of fever, weight loss, hemorrhoids or abdominal masses. These are symptoms that are not associated with IBS, however they prompt additional investigation.3
What occurs in an IBS physical exam?
During a physical exam, a doctor examines the patient’s body for signs of disease. The doctor will include a visual inspection (looking), palpation (feeling), ascultation (listening, often with a stethoscope), and percussion (producing sounds through tapping).4
Components of a physical exam in diagnosing IBS
Palpation of the abdomen in patients with IBS may reveal tenderness. In women, a pelvic exam should be performed to rule out conditions related to the ovaries and uterus, which can produce symptoms that mimic IBS. A physical exam for IBS should include a digital rectal exam, including a test for occult blood. A fecal occult blood test (FOBT) checks for hidden (occult) blood in the stool (feces), which is not associated with IBS but does require further medical evaluation and testing.5
Patients aged 50 years and older should have more extensive testing, including a colonoscopy. Anyone age 50 or older who has IBS-like symptoms should have a colonoscopy as part of a routine screening examination to rule out colon cancer. For people who have a family history of colon cancer (particularly in a parent, brother or sister) the recommended age for screening colonoscopy is 40 years old. African Americans are more likely to develop colon cancer at an earlier age and should also consider colonoscopy screening at age 40.6
Rarely, doctors may perform an upper endoscopy to investigate certain symptoms like persistent diarrhea that does not sound like IBS or a CT scan to further investigate the abdominal organs, particularly the pancreas, gall bladder and liver as well as the intestines. Exploratory surgery is rarely required for the diagnosis of IBS and is generally avoided. Studies have shown that surgery done only for an indication of IBS-like pain is usually not helpful in finding the cause of the patient's pain and rarely leads to improvement in a patient's pain symptoms.6 Before exploratory surgery is considered, doctors may perform other tests, such as a colonoscopy or lower GI series to rule out other gastrointestinal disorders.
Next steps in diagnosing IBS
If the physical examination does not identify any symptoms that the doctor wants to investigate further, additional tests may be done to diagnose IBS. Physicians commonly run blood tests and may also do a stool analysis to rule out bacteria, parasites or inflammatory bowel disease. Other tests that may be conducted include a lactose intolerance test, a breath test, a lower GI x-ray or a CT scan.