Preparing for gastroscopy and colonoscopy

Gastroscopy is an endoscopic examination of the oesophagus, stomach and duodenum, and colonoscopy is an examination of the large bowel and rectum. In both, the doctor uses a flexible instrument with a camera to see the lining directly and, if needed, takes small tissue samples; during a colonoscopy, polyps can also be removed during the test itself.

You come to a gastroscopy fasting. You will be told when you book how many hours before the procedure you must not eat or drink. Before the test the throat is numbed locally with a spray, and a sedative is also available. The test is short and most people describe it as unpleasant rather than painful. Afterwards your throat stays numb from the spray for a while, so wait as long as you are told before eating and drinking; swallowing during this time is less safe than it seems.

For a colonoscopy the preparation is more demanding, and how much can be seen depends on it. Your diet is adjusted a few days beforehand, and before the examination you drink a laxative solution according to a precise schedule. The schedule is not a recommendation but part of the test: a poorly cleaned bowel means poorer visibility and sometimes repeating the whole procedure.

Drink the laxative solution at the pace set by the instructions, not all at once. Plan to be at home and near a toilet during this time. Many people find it easier if the solution is chilled. Between sips, clear fluids are allowed, except those the instructions specifically advise against.

Blood-thinning medicines and medicines for diabetes need special preparation. Mention them when you book and do not adjust the instructions yourself. The same goes for iron preparations, which are usually paused before a colonoscopy, and for regular treatment, which most people continue to take.

If you receive a sedative or analgosedation, you must not drive that day and you need someone to accompany you home. For colonoscopy this is not an exception but a common choice, so arrange transport in advance. Expect the day of the test to take considerably more time than the procedure itself.

You will get a verbal explanation of the findings after the test, once you have recovered, and a written report as agreed during your visit. If tissue samples were taken, the histology report arrives later. Further steps are agreed on the basis of the complete report, not only on what was seen during the test. Bloating after a colonoscopy is expected and passes once the air is expelled; walking helps. If severe abdominal pain, fever or heavier bleeding occurs after either test, do not wait for the follow-up appointment but seek emergency medical help.

Both tests are carried out with a referral from the Health Insurance Institute of Slovenia (ZZZS) and on a self-pay basis. With a referral you book through the booking for referred patients; without one, you book as a self-paying patient. Booking is managed by the provider that carries out the test. The instructions you receive from them take precedence over general advice found online.