Crohn’s disease is diagnosed through a combination of medical history, physical examination, and a set of tests rather than a single definitive test. The process looks for evidence of inflammation, determines where the disease is active, and rules out other conditions with similar symptoms. Key steps typically include:
- Medical history and physical exam
- Your doctor will ask about your symptoms (such as abdominal pain, diarrhea, weight loss), smoking status, family history, and prior illnesses, then perform a physical exam to check for abdominal tenderness and other signs of inflammation or malnutrition. This foundational step helps guide further testing.
- Laboratory tests
- Blood tests can detect anemia, low protein levels, or signs of inflammation (for example, elevated C-reactive protein or erythrocyte sedimentation rate). They also help assess overall health and screen for complications.
- Stool tests may be done to rule out infections or other causes of diarrhea and to look for inflammatory markers in the gut.
- Endoscopy and biopsy
- Colonoscopy is the most common procedure for diagnosing Crohn’s disease. A flexible tube with a camera is used to inspect the colon and the end of the small intestine (ileum). Biopsies taken during the procedure can show characteristic tissue changes.
- In some cases, an upper endoscopy (esophagogastroduodenoscopy) may be performed to examine the upper GI tract if symptoms suggest involvement there.
- Imaging studies
- Cross-sectional imaging such as CT enterography or MR enterography provides detailed pictures of the small intestine and surrounding tissues, helping to identify areas of inflammation, strictures, or fistulas that aren’t easily seen with endoscopy.
- Plain CT or MRI may be used depending on the clinical scenario and need to minimize radiation exposure, especially in younger patients.
- Capsule endoscopy
- In select cases, swallowing a small camera capsule can visualize parts of the small intestine not reached by standard endoscopy. This is usually considered when other tests don’t clearly establish a diagnosis and there’s no suspected narrowed or blocked bowel.
- Exclusion of other conditions
- Because symptoms overlap with infections, irritable bowel syndrome, ulcerative colitis, and other GI diseases, the diagnostic process often includes tests to rule out these alternatives.
Important notes for understanding:
- There is no single “Crohn’s test.” Diagnosis depends on integrating clinical presentation with findings from endoscopy, histology (biopsy), imaging, and labs.
- The pattern of disease (which parts of the GI tract are involved and whether there are complications like fistulas or strictures) guides treatment planning.
- In some cases, a diagnosis may be made after monitoring over time and repeating evaluations if symptoms persist or evolve.
If you’d like, share your current symptoms and any test results, and I can outline how clinicians typically interpret those in the context of Crohn’s disease.
