Crohn’s is a disease that primarily affects the digestive system. According to the National Library of Medicine (NIH), Crohn’s “involves an abnormal immune response that causes excess inflammation. It most often affects the intestinal walls, particularly in the lower part of the small intestine and portions of the large intestine.”
Inflammation can occur in any part of the digestive system, which can cause ulcers. Individuals with Crohn’s disease often experience:
Crohn’s disease is a form of inflammatory bowel disease (IBD).
IBDs are generally diagnosed using an endoscopy, colonoscopy, radiologic and blood or stool tests. For Crohn's disease specifically, there is no single test that can confirm Crohn's. Crohn's symptoms are often similar to other conditions like bacterial infections. Healthcare providers will use medical history and diagnostic testing to exclude potential causes of symptoms before diagnosing Crohn's. The process can often take some time.
For more information regarding diagnosing testing, the Crohn's and Colitis Foundation and National Institute of Diabetes, Digestive and Kidney Diseases provide detailed descriptions of the diagnosis process.