How is ulcerative colitis diagnosed?
Diagnosis is made based on symptoms and the exclusion of other diseases by observation of typical findings at endoscopy and failure to find evidence of infection. The presence of often bloody diarrhea will prompt your doctor to perform an endoscopic examination; either a sigmoidoscopy and/or colonoscopy (described below). If inflammation is seen by these techniques, the physician will then attempt to rule out an infectious cause with stool cultures and blood tests. Usually it is possible to tell the difference between CD and UC but not always. Particularly, there may be some uncertainty between a diagnosis of UC and CD affecting the colon; this is termed indeterminate colitis. Occasionally a diagnosis of UC will eventually turn out to be CD.
