Crohn's is an inflammatory condition that can affect any part of the gut. Over half a million people in the UK live with Crohn's disease and about a quarter will develop a fistula near their back passage. A fistula is an abnormal connection between two surfaces of the body. These can be hard to treat causing pain and infection. Surgery is required to control infection and in extreme cases this can lead to incontinence or even formation of a stoma, when the bowel is brought to the skin and waste goes into a bag on the tummy wall. Patients with perianal Crohn's are usually referred to a surgeon by their medical team and subsequently undergo a MRI scan and an examination under anaesthesia (EUA) where abscesses (regions of fluid build-up) will be drained and a seton (plastic sling or suture) inserted through the fistula, or the fistula opened to the skin if this will not affect continence. They are then started on specialist medication by the gastroenterologists (gut doctors). Abscesses or fistulas can be difficult to identify during EUA, leading to ongoing infection and repeat procedures. This causes additional scarring and delays the medical treatment that can allow fistulas to heal. Multiple or incorrectly performed operations can also damage the muscles that help hold stool in the back passage, leading to incontinence. We believe that improving how information is communicated between radiology (who report scans) and surgeons will improve their ability to identify and manage all fistulas and collections at operation. Here is a typical MRI report given to the surgeon by the radiologist: \'There is a low intersphincteric fistula with predicted internal opening in the lower half of the anal canal at dentate line level between 5-6 o'clock that passes in the intersphincteric plane to the anal verge between 5-6 o\'clock.\' This protocol was developed in an era when written communication was really the only way to convey information between specialists. Jargon aside, surgeons face significant difficulty interpreting such written descriptions of a complex 3D structure and using it as a surgical guide. Indeed, a major complaint from surgeons is how difficult it is to get real value from these preoperative MRIs, which cost time and money. With advances in digital technology, we believe this system can be vastly improved. Motilent (a UK SME specialising in technology to improve the management of Crohn\'s Disease) has developed a sophisticated visualisation tool to provide a 3D model of the fistula and surrounding structures, we call this tool Virtual EUA (vEUA), allowing the surgeon to better understand the anatomy of the problem in conjunction with radiology. We are aiming to establish whether vEUA changes the behaviour of colorectal surgeons, increasing confidence in identifying and dealing with fistulas, which will reduce the number of surgical procedures required and improve the quality of care, resulting in a cost saving for the hospital and a much-needed step towards more effective management of perianal Crohn\'s. Any patient taking part in the trial will be randomly allocated to have the 3D model utilised in their care or standard care. We will use pre- and post-surgical patient questionnaires, surgical questionnaires and MRI imaging to establish if vEUA is safe and effective in improving the care of patients with perianal Crohn\'s.