An endoscopy is a procedure where organs inside your body are looked at using an instrument called an endoscope.

An endoscope is a long, thin, flexible tube that has a light and camera at one end. Images of the inside of your body are shown on a television screen.

Endoscopes can be put into the body through the mouth and down the throat, or through the bottom.

An endoscope can also be put inside the body through a small cut (incision) made in the skin when keyhole surgery is being done.

When an endoscopy is used

An endoscopy can be used to:

  • investigate unusual symptoms
  • help perform certain types of surgery

An endoscope can also be used to remove a small sample of tissue to be looked at more closely. This is called a biopsy.

Investigating symptoms

An endoscopy might be recommended to investigate many symptoms, including:

If the food pipe (oesophagus), stomach, or top part of the small intestine need to be looked at, it's known as a gastroscopy

If the bowel needs to be looked at, it's known as a colonoscopy.

Other types of endoscopies used to investigate symptoms include: 

  • bronchoscopy – used to look at the airways if you have a cough that is not getting better or you're coughing up blood
  • hysteroscopy – used to look inside the womb (uterus) if there are problems such as irregular periods or if you have more than 1 miscarriage
  • cystoscopy – used to look inside of the bladder if there are problems like urinary incontinence or blood in your pee
  • flexible sigmoidoscopy – used to look inside the lower part of the bowel
  • endoscopic ultrasound – used to take images of internal organs, such as the pancreas, and take tissue samples
  • wireless capsule endoscopy – involves swallowing a small capsule that has a camera and light in it, which sends pictures to a computer

Endoscopy to help with treatment

Sometimes endoscopy is used to help with certain types of surgery.

This includes keyhole surgery (laparoscopic surgery) and surgery to repair damage inside joints (arthroscopy).

What happens during an endoscopy

Endoscopies are usually done in hospital.

Before having an endoscopy

Depending on what part of your body is being looked at, you will probably be asked to avoid eating and drinking for several hours before you have an endoscopy.

You may be given a laxative to help clear your bowels if you're having a colonoscopy to examine the large intestine, or a sigmoidoscopy to examine the rectum and lower part of the bowel. You will usually also be asked to eat a low-fibre diet in the days before you have a colonoscopy.

In some cases, you may also need antibiotics to reduce the risk of an infection.

If you're taking a medicine to thin your blood, such as warfarin or clopidogrel, you may need to stop taking it for a few days before having an endoscopy. This is to help prevent bleeding during the procedure.

However, do not stop taking any prescribed medicine unless a GP or specialist tells you to.

During an endoscopy procedure

An endoscopy is not usually painful, but it can be uncomfortable. Most people only have mild discomfort, similar to indigestion or a sore throat.

The procedure is usually done while you're awake. You may be given a local anaesthetic to numb a specific area of your body. This may be in the form of a spray or lozenge to numb your throat, for example.

You may also be offered a sedative to help you relax and make you less aware of what's going on around you.

The endoscope will be carefully put into your body. Depending on the part of your body being looked at, it may be put into your:

  • mouth and down your throat
  • bottom (anus)
  • urethra – the tube that you pee through

An endoscopy usually takes between 15 and 45 minutes, depending on what it's being used for. You can usually go home the same day and do not have to stay in hospital overnight.

Wireless capsule endoscopy

You swallow a small capsule with a camera and light in it. The capsule sends images of the inside of your body to a computer for a doctor to look at.

The capsule is the size of a large tablet and leaves your body naturally when you go to the toilet.

It's often used if you have any internal bleeding and there's no obvious cause.

There are some complications associated with wireless capsule endoscopy. It can be difficult to swallow the capsule and to pass it naturally. The capsule can also get caught in the narrow areas of your bowel, causing a blockage.

After an endoscopy

If you have a sedative, you'll probably need to rest for about 1 to 2 hours after having an endoscopy.

If you have a sedative, a friend or relative will also need to take you home after the procedure and stay with you for 24 hours.

If you do not have a sedative, you can go home soon after you have had an endoscopy.


An endoscopy is usually a safe procedure, and the risk of serious complications is very low.

Rare complications include:

  • an infection in a part of the body the endoscope is used to examine – this may require treatment with antibiotics
  • piercing or tearing (perforation) of an organ, or bleeding – you may need surgery to repair any damage


Sedation is usually safe, but it can sometimes cause side effects, including:

When to seek medical help

See a GP if you notice any signs of infection.

Signs of infection include:

  • redness, pain or swelling near where the endoscope was put in
  • a discharge of fluid or pus near where the endoscope was put in
  • a very high temperature, or feeling hot or shivery

Other signs of a possible complication after having an endoscopy include:

See a GP or visit your nearest A&E immediately if you notice any of these signs or symptoms.

Page last reviewed: Sun Dec 2022 Next review due: Sun Dec 2022

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