The exclusion of non-functional disease in patients with suspected IBS is an important concern. There are many tests designed to exclude non-functional diseases. The primary issue, however, is to decide which tests are reasonable to perform. Tests are selected individually since each case different. Nevertheless, there are some basic tests that are often performed to exclude non-functional gastrointestinal disease. These tests identify anatomic (structural) and histological (microscopic) diseases of the intestines.
The endoscopic tests include:
For examination of the small intestine, there is also a capsule containing a tiny camera that can be swallowed (capsule endoscopy). As the capsule travels through the intestines, it sends pictures of the inside of the intestines to an external recorder for later review. However, the capsule is not widely available and its value in IBS has not yet been proven.
X-rays are easier to perform and are less costly than endoscopies. The skills necessary to perform X-rays, however, are becoming rarer among radiologists because they are doing them less often. Therefore, the quality of the X-rays often is not as high as it used to be. As noted above, endoscopies have an advantage over X-rays because at the time of endoscopies, biopsies can be taken to diagnose or exclude histological diseases, something that X-rays cannot do.
- As always, a detailed history from the patient and a physical examination frequently will suggest the cause of the symptoms.Routine screening blood tests are performed looking for clues to unsuspected diseases.
- Examination of stool also is a part of the evaluation since it may reveal infection, signs of inflammation, or blood and direct further diagnostic testing. Sensitive stool testing (antigen/antibody) for Giardia lamblia would be reasonable because this parasitic infection is common and can be acute or chronic.
- Some physicians do blood testing for celiac disease (sprue), but the value of doing this is unclear. Moreover, if an EGD is planned, biopsies (taking samples of tissue) of the duodenum usually will make the diagnosis of celiac disease.
- Both X-rays and endoscopies can identify anatomic diseases. Only endoscopies, however, can diagnose histological diseases because biopsies can be taken during the procedure. The X-ray tests include:
- The esophagram and video-fluoroscopic swallowing study to examine the esophagus
- The upper gastrointestinal series to examine the stomach and duodenum
- The small bowel series to examine the small intestine
- The barium enema to examine the colon and terminal ileum.
The endoscopic tests include:
- Upper gastrointestinal endoscopy (esophago-gastro-duodenoscopy, or EGD) to examine the esophagus, stomach, and duodenum
- Colonoscopy to examine the colon and terminal ileum
- Endoscopy also is available to examine the small intestine, but this type of endoscopy is complex, not widely available, and of unproven value in suspected IBS.
For examination of the small intestine, there is also a capsule containing a tiny camera that can be swallowed (capsule endoscopy). As the capsule travels through the intestines, it sends pictures of the inside of the intestines to an external recorder for later review. However, the capsule is not widely available and its value in IBS has not yet been proven.
X-rays are easier to perform and are less costly than endoscopies. The skills necessary to perform X-rays, however, are becoming rarer among radiologists because they are doing them less often. Therefore, the quality of the X-rays often is not as high as it used to be. As noted above, endoscopies have an advantage over X-rays because at the time of endoscopies, biopsies can be taken to diagnose or exclude histological diseases, something that X-rays cannot do.
