Patients with inflammatory bowel disease—especially those with Crohn disease—typically experience discomfort for 3 to 5 years before the true cause of their symptoms is identified. Symptoms are often attributed to a more common problem, such as infection or irritable bowel syndrome. Also, 20% to 40% of patients with Crohn disease or ulcerative colitis have involvement outside of the bowel that manifests as back pain, joint pain, mouth ulcerations, pyoderma gangrenosum in the legs, or erythema nodosum of the shins. These extraintestinal “red herrings” can obscure the diagnosis. This colonoscopic image shows moderate to severe inflammation of the ileum that is typical of Crohn disease.