Exposure to ionising radiation as a result of diagnostic imaging is increasing among patients with inflammatory bowel disease (IBD), primarily due to the more widespread use of computed tomography (CT). The potentially harmful effects of ionising radiation are a major cause for concern and radiologists, technologists and referring physicians who have a responsibility to the patient to ensure judicious use of those imaging modalities which result in exposure to ionising radiation and, when imaging is necessary, to ensure that a diagnostic quality imaging examination is acquired with lowest possible radiation exposure. This can be achieved by limiting the use of those imaging studies which involve ionising radiation to clinical situations where they are likely to change management, by implementing advances in low-dose CT technology, and, where feasible, by using alternative imaging modalities, such as ultrasonography or magnetic resonance imaging, which avoid radiation exposure.