Because there is no single conclusive diagnostic test for Crohn's disease, a doctor will need to base a diagnosis of Crohn's on a physical examination, the patient's medical history, and results of any laboratory or imaging tests.
To make a diagnosis even more difficult, Crohn's disease is often mistaken for another other serious conditions, such as inflammatory bowel disease (IBD) and ulcerative colitis. There are, however, some marked differences. Unlike with ulcerative colitis, a patient with Crohn's may develop fistulas and abscesses around the anus as well as ulcers within the anal canal itself. This occurs because Crohn's disease penetrates into the deepest layers of the bowel lining, while ulcerative colitis is restricted to the top layers. Also, Crohn's disease may affect any part of the gastrointestinal (GI) tract, while ulcerative colitis is confined to the colon (large bowel).
Your First Appointment
In order to make a proper diagnosis, your doctor will want to know your symptoms, medical history, and the types and doses of any medications you’re taking. Be prepared to describe your symptoms in detail—without self-diagnosing—and come prepared with a list of questions and a notebook to take careful notes.
The doctor will be on the lookout for symptoms that point to Crohn's such as "crampy" abdominal pain, frequent diarrhea, and rectal bleeding. Often a person with Crohn's will lose weight because eating becomes a painful endeavor. Other symptoms may include urgent bowel movements, chronic fatigue, and increased gas.
Another clue that it may be Crohn's is the existence of a large, painful area of swelling located in the lower right-side of the abdomen. Perianal disease—those fistulas and abscesses around the anus—almost always point to Crohn's disease.
The first test your doctor will order is probably a blood test. A blood test can reveal whether or not you’re absorbing nutrients properly, if there’s inflammation somewhere in the body, or if you have anemia.
A stool test can look for an infection or blood in the intestines. If your symptoms suggest something other than Crohn's, your doctor may test for another condition. For example, if they suspect lactose intolerance, they may perform what is known as a breath test. If lactose is being metabolized in the colon rather than the small intestine, it releases hydrogen, which can be measured in the breath.
If Crohn's isn’t ruled out with early tests, your doctor may order additional tests. These may include a barium enema (a procedure that uses x-ray imaging to look for disease in the large bowel) or a GI series in which x-rays are used to look at the small bowel. Other, more sophisticated imaging technologies such as an MRI or CT scans may also be performed.
A colonoscopy, endoscopy, or sigmoidoscopy may be ordered to look inside and perhaps to remove sample tissue from different areas of the bowel. A biopsy on the tissue may confirm or deny a diagnosis of Crohn's. Your doctor may perform an enteroscopy, mainly to rule out other conditions, as it doesn't reach areas of the bowel where Crohn's is most often found.
A Diagnosis of Crohn's Disease
Your doctor should be compassionate and understanding when presenting you with a diagnosis of Crohn's for the first time. Patients often experience a wave of different emotions upon diagnosis that may range from anger at having to live with a chronic disease to relief of finally knowing what was behind their symptoms. Your doctor should reassure you that, although there is currently no cure, Crohn's disease is a treatable illness. In fact, many with the disease lead productive and active lives.
Because there is no cure for Crohn's, medical treatments are designed to reduce inflammation and induce remission. Medications used to treat Crohn's disease today include anti-inflammatory drugs in the aminosalicylate (5-ASA) class, corticosteroids such as prednisone, and immune modifiers like azathioprine and 6-MP. Other treatments may include antibiotics and biologic therapies (which may provide relief for those patients who don't respond well to traditional therapies).
Surgery is sometimes needed to prevent complications or to relieve more serious symptoms. A good doctor will make you aware of new treatments and advances in medications—many of which are on the horizon—and answer any questions you may have every step of the way.