Benefits and Risks

The procedure will help us to investigate your symptoms and it may help us to treat you.

Gastroscopy and colonoscopy procedures are generally safe, but all procedures have some risks, which you should discuss with your doctor. These are the more common risks:

Gastroscopy 

• Sore throat which should wear off within 24 hours 

• Complications such as bleeding or damaging the gastrointestinal tract are very rare for example about one in 3,000 risk of bleeding or tearing (perforation) of the gut. This risk is increased to one in 100 if biopsies are taken when infection and inflammation may also occur. An operation is likely to be needed for perforation and this is likely to be on the same day.

• Other rare complications include inflammation of the lungs (aspiration pneumonia) and a reaction to the intravenous sedative drugs or local anaesthetic spray. 

• Upper gastrointestinal endoscopies may involve a slight risk to crowned teeth or dental bridgework. These risks occur in less than one in 100 procedures 

Colonoscopy 

• Wind and discomfort 

• There is a small risk of tearing the bowel (perforation) during the colonoscopy. The risk of this is about one in 1000 procedures. An operation is usually needed for perforation and this is likely to be on the same day.

• If a polyp is seen and removed this increases the risk of perforation to about one in 500 procedures, though the risk is greater with certain types of polyp. 

• Bleeding can happen and is usually controlled during the procedure. Very rarely, surgery is necessary.

• If a polyp is removed, very rarely, the site from which it was removed may start to bleed at any time up to two weeks later.

What happens afterwards? 

• If you have not had sedation, you can leave as soon as you feel ready once your paperwork is complete.

• If your gastroscopy procedure was carried out with a local anaesthetic throat spray you must wait until the throat spray has worn off before you eat and drink. This usually takes about 30 minutes but may take up to two hours. 

• If you used ‘gas and air’ (entonox) during the colonoscopy procedure, you should be able to leave after 30 minutes as its sedative effects wear off quickly. Your blood pressure and pulse will be monitored. 

• If you have had sedation, you will need to rest in the recovery area until you are fully awake (usually an hour and a half). Your blood pressure and pulse will be monitored. An adult must be available to escort you home as the sedation impairs your reflexes and judgement. 

• You will be informed of the time you are allowed to eat and drink. The nurse will give you refreshments at this time.