Everything you Need to Know About an Endoscopy

What is an endoscopy?

An endoscopy is a medical procedure in which an instrument (an endoscope, or ‘scope’) is introduced into the body to gain a view of internal structures and organs. This procedure is used to investigate symptoms and diagnose conditions, as well as to deliver treatments. There are many different types of endoscopy, dependent on the purpose of the procedure, the internal structures that are being looked at and the equipment being used.

The main types are summarised in the tables below.

Applications of endoscopy:


Often, this procedure is purely for the visualisation of tissues in certain regions, and this can be sufficient for diagnosing certain conditions. An endoscope can also allow you to take small tissue samples (biopsies) for additional diagnostic testing.


Endoscopic equipment can be used to deliver treatments such as:

  • Repair of bleeding stomach ulcers
  • Removal of fibroids or small tumours
  • Removal of stones (bladder or kidney stones, or gallstones)
  • Repair of certain joint problems (‘arthroscopy’)

These can be achieved without the need for open surgery.

Endoscopic ultrasound

For some procedures, endoscopy is used in combination with ultrasound imaging. This can be used to get a better view of deeper internal structures and to guide trickier biopsies and stone removal.

Laparoscopic surgery

Sometimes known as ‘key-hole surgery’, this approach involves making a few small incisions in the skin and introducing endoscopes and modified surgical tools to perform an internal operation using the endoscopic cameras. Where appropriate, this can reduce many of the risks associated with open surgery, and results in improved quality-of-life outcomes for many surgical procedures.

Types of scope:

Conventional scope

A normal endoscope consists of a long, thin, flexible tube with a light and a camera on its end. There are variations in the structure of the endoscope itself depending on its purpose and whether or not additional biopsy/treatment is required.

Wireless capsule endoscope

First introduced in 2001, this is quite different to a conventional endoscope and involves swallowing a small camera (about the size of a large pill), which travels down the gastrointestinal (GI) tract and is passed out of the bowel normally. The video footage can then be examined for diagnostic signs.

Why would I need an endoscopy?

The main indication for a diagnostic endoscopy is an investigation of symptoms or other abnormal investigations, some of which are summarised below:

Procedure by location:



Upper endoscopy/gastroscopy The upper GI tract, including oesophagus, stomach and first part of the small intestine if needed Problems swallowing, persistent nausea, vomiting or abdominal pain, vomiting blood, unexplained weight loss
Colonoscopy The lower GI tract, mainly the large bowel Unexplained change in bowel habit, persistent diarrhoea, blood in stools, unexplained weight loss
Bronchoscopy The airways in the lungs Persistent cough, coughing up blood, abnormal chest x-ray, persistent or abnormal lung infection
Hysteroscopy The inside of the uterus (womb) Irregular vaginal bleeding, recurrent miscarriages
Cystoscopy The inside of the bladder Blood in urine, urinary incontinence, recurrent urinary tract infections, persistent pelvic pain

What happens with an endoscopy?

Preparing for an endoscopy

Before your endoscopy, there are some steps you need to take to make sure that you are prepared for the procedure:

Eating and drinking
  • If you are having any procedure involving a general anaesthetic, you should not eat for 6-8 hours before the procedure. You can drink clear fluids up until 2 hours before. This also applies if you are having any procedure involving the GI tract (upper endoscopy) or a bronchoscopy
  • If you are having a colonoscopy, you will need to avoid certain foods in the days leading up to the procedure (talk to your doctor about what you need to avoid). You will also need to take a laxative the day before the colonoscopy to help clear out the bowel
  • If you are having a cystoscopy or hysteroscopy under a local anaesthetic only, then you can eat and drink normally beforehand
  • It is important to check all of your medications prior to an invasive procedure
  • If you are taking any blood-thinning tablets like warfarin or clopidogrel, you may need to stop taking these a few days before
  • Some medications that alter bowel habit (including some types of painkillers), may also need to be stopped if you are having a colonoscopy
  • Your doctor will discuss any necessary changes in medications leading up to your endoscopy

The procedure

The endoscopy itself will most likely take place in a hospital as an outpatient procedure (you won’t be admitted or need to stay overnight), although some larger GP practices also have facilities to perform endoscopies.

  • Before the procedure begins, you will be given a local anaesthetic where the endoscope will be inserted (this may be in the throat, anus, or urethra depending on what system is being looked at). This will numb the area so that the endoscopy is not painful, although it may still feel a little uncomfortable
  • If you are having a general anaesthetic, then you will be asleep for the entire procedure
  • If you are having an endoscopy with local anaesthetic, you will also be offered sedation, which can help you to relax throughout the procedure and reduce discomfort.

Most endoscopies take between 15 minutes and 1 hour to complete, and you will be monitored carefully throughout. If there are any problems during the endoscopy, you can speak to the specialist and they may be able to alter what they are doing or stop the procedure if needed.

After the endoscopy

Following the endoscopy, it is recommended that you rest for a while to recover:

  • If you have had a local anaesthetic only, this will take an hour or so to wear off
  • If you have had any sedation, you may be drowsy for the following 24 hours. During this time, it is important that you do not drive, do not drink alcohol and do not operate machinery. It is recommended that you arrange an alternative way to get home

You may also experience a small amount of bleeding from the endoscopy site:

  • Cystoscopy – you can expect to have blood in the urine for up to 24 hours afterwards
  • Colonoscopy – you may have some blood in the stools which should settle after a day or so

If you have any significant or prolonged bleeding, then you should see your GP.

What are the risks of endoscopy?

Overall, endoscopy is a very safe procedure, with a low risk of complications and adverse outcomes. However, there are a few potential risks to be aware of:

  • Perforation
    • This is when the scope breaks through the wall of the organ being looked at. This is a very rare complication, occurring in only 1-2 cases per 1,000 colonoscopies, for example, and is managed immediately with surgery
  • Reaction to sedation
    • Mild reactions to sedation (such as nausea) are not uncommon, however, more serious adverse reactions and allergic reaction or anaphylaxis, whilst rarer, are also potential complications, and are monitored for throughout the procedure
  • Infection
    • Any invasive medical procedure can carry the risk of introducing infection, although all precautions necessary are taken to minimise this risk. If you have any signs of infection following an endoscopy (such as redness, pain, swelling or a high fever), you should see your GP. If an infection does occur, it can be treated with antibiotics
  • Bleeding
    • If there is any significant bleeding during the procedure, this will be managed appropriately. Sometimes there can be bleeding after the procedure, in which case you should see your GP as soon as possible
  • Pancreatitis
    • A specific procedure called ‘Endoscopic Retrograde Cholangiopancreatography’ (more commonly abbreviated to ERCP), which looks at the pancreas and biliary system carries a risk of inducing pancreatitis (inflammation in the pancreas) in around 10% of cases

If you experience any of the following symptoms following an endoscopy, you should see your GP as soon as possible or go to your nearest A&E:

  • Black or dark-coloured stools
  • Shortness of breath
  • Chest pain
  • Severe and persistent abdominal pain
  • Vomiting blood

To find out more call us on 020 8341 4182 or make an online enquiry.

Date: 22/02/2019
By: gpittson