Depending on the exact nature of the procedure and its objectives, an endoscopy can take anywhere between 15 and 60 minutes to carry out. It will usually be performed on an outpatient basis, which means you will not have to stay in hospital overnight.he endoscopy procedure. An endoscopy is not usually painful, although it may feel uncomfortable. Endoscopies do not usually require a general anaesthetic (with the exception of an arthroscopy). However, you may be given a local anaesthetic to numb a specific area of your body.