Blood and stool tests may be used to confirm or rule out enteritis from an infection. However, food poisoning is often diagnosed based on the symptoms.  When symptoms become concerning, it might be necessary to do testing to see what is causing them. Imaging tests such as computed tomography (CT) which uses X-rays for a detailed image, or magnetic resonance enteroclysis (MRE) which uses magnetic fields might be helpful. Endoscopy, using a thin, flexible tube with a camera and a light on the end to see the inside of the digestive system, might also be used. A test in which patients swallow a pill with a camera in it, called small bowel capsule endoscopy, is also sometimes used to make a diagnosis.