Crohn's disease primarily affects adolescents and young adults, according to the Crohn's and Colitis Foundation of America (CCFA). This inflammatory bowel disease is characterized by abdominal pain, cramping and chronic diarrhea, but those who have this disease may also complain of poor appetite and weight loss, fevers and rectal bleeding. The CCFA notes that the symptoms of Crohn's, which is also sometimes called regional enteritis, vary widely, and many are similar to the symptoms found in other disorders. For these reasons, a lot of time and a number of tests may be required to rule out other possibilities and confirm the diagnosis of Crohn's disease.
History and Physical
For those who are experiencing persistent diarrhea along with abdominal pain or cramping, especially in the right lower area of the abdomen, it's a good idea to make an appointment with a physician to have a complete history and physical. You can prepare for this appointment by thinking in advance about some questions the Mayo Clinic suggests your doctor may ask, including: when you first noticed the symptoms; if they are continuous or intermittent and how severe they are; what makes the symptoms worse and what seems to lessen them; how the symptoms impact your daily life; and if you smoke, or use ibuprofen or other non-steroidal anti-inflammatory medications.
According to the American Medical Association's online JAMA Patient Page about Crohn's, you might be referred to a gastroenterologist, a doctor who specializes in diseases such as Crohn's.
Laboratory Tests
There is no laboratory test that will directly determine Crohn's, according to the online Merck Manual Home Edition for Patients. However, your doctor will want to rule out as many other conditions as possible before diagnosing Crohn's, so he may order a number of laboratory tests. Among them are:
Blood tests to check for a high white blood cell count, which tells the doctor that you are experiencing an inflammatory reaction. A blood test might also check for anemia, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Anemia is sometimes a sign of bleeding in the intestines.
Two tests may be done that look for certain antibodies in the blood that are associated with Crohn's, according to the Mayo Clinic, which also notes that not everyone with Crohn's has these antibodies, nor is their presence or absence diagnostic by itself.
Finally, a stool sample will be tested for blood and also to be sure that your symptoms aren't the result of an infection, because, as the CCFA points out, the symptoms for an infection are so similar to those of Crohn's disease.
X-Rays
Various kinds of imaging exams allow physicians to see the areas of the gastrointestinal (GI) tract that are of particular concern in diagnosing Crohn's disease. Among these are:
The upper and lower GI series of x-rays are done after a patient is given a barium solution, which appears in white when x-rays are taken of the intestines a short time later. Your doctor will be looking for areas of inflammation or other abnormalities in the GI tract. According to the Merck Manual, this type of x-ray exam can almost always detect Crohn's disease.
Computerized tomography (CT) or magnetic resonance imaging (MRI) may also be used to look at your intestines, depending on the area the physician wants to pinpoint for the exam. The Merck Manual says that CT helps distinguish between Crohn's and ulcerative colitis, and this type of imaging is best able to detect abscesses or fistulas occurring outside the walls of the intestinal tract. According to the Mayo Clinic, while these tests are not as invasive as a colonoscopy, they do expose you to increased amounts of radiation vs. a standard x-ray.
Endoscopy
A common test to look for inflammatory bowel disease, including Crohn's, is to have one of two endoscopic procedures, either a colonoscopy or a sigmoidoscopy. For these exams, your physician will insert a flexible lighted tube into your anus. The tube has a camera on it, which sends pictures to a computer monitor, so the inside of your intestines can be viewed directly, making it easier to identify areas of inflammation, ulceration or bleeding. According to the National Institute of Diabetes and Digestive and Kidney Diseases, the colonoscopy allows the doctor to see the entire large intestine, while the sigmoidoscopy looks only at the lower part of the large intestine.
According to the CCFA, during an endoscopy, your physician may also do a biopsy, meaning she will remove a small bit of tissue for later laboratory analysis, which may help to confirm the diagnosis of Crohn's disease.
