8 Types of GI Endoscopy Explained: What Each Test Looks At

At a glance: "Endoscopy" covers several different tests. Some use a flexible tube with a camera, some use a camera you swallow, and some combine a camera with ultrasound or X-rays. They look at different parts of the digestive system, and only some of them can take tissue samples or treat a problem during the same procedure. This guide explains eight of the most common types, how they differ, and which ones SinoCareLink can arrange in China.

Which test is right for you depends on your symptoms and medical history, and that is a decision for your own doctor. If you have symptoms such as difficulty swallowing, vomiting blood, black stools, blood in your stools or unexplained weight loss, please speak to a doctor promptly rather than waiting to book a test abroad.

The eight types at a glance

1. Gastroscopy (upper endoscopy, OGD)

A thin, flexible tube with a camera is passed through your mouth to look at your food pipe (oesophagus), stomach and the first part of your small intestine (NHS). It is used to find the cause of symptoms such as indigestion or difficulty swallowing, and the doctor can take small tissue samples (biopsies) or treat some problems during the same test (NHS).

In the UK you are usually asked not to eat for at least 6 hours beforehand; other countries and hospitals use different fasting times, so follow your hospital's instructions. UK patients are usually awake, with a throat spray or medicine to help them relax. If you have sedation, the NHS advises not driving or drinking alcohol for 24 hours afterwards. Complications are rare, but can include a reaction to the sedation, bleeding or infection (NHS).

2. Colonoscopy

A colonoscopy uses a longer flexible tube passed through the bottom to look at the whole large bowel and rectum. During the same procedure the doctor can take biopsies and remove growths called polyps (Mayo Clinic). The bowel has to be emptied first: the NHS describes eating plain foods for 2 days and drinking laxative sachets the day before (NHS).

In the UK, people are usually awake during a colonoscopy and are offered painkillers, sedation or gas and air, although not every hospital offers all of these (NHS); in the US, Mayo Clinic says sedation or anaesthesia is usually recommended (Mayo Clinic). In rare cases people react to the sedation, have heavy bleeding afterwards or get a small tear in the bowel (NHS).

In England's bowel screening programme, people aged 50 to 74 are sent a home stool test (FIT) every 2 years, and a colonoscopy is usually offered if the result shows further tests are needed (NHS; GOV.UK).

3. Flexible sigmoidoscopy

A flexible sigmoidoscopy looks at the rectum and the left side of the large bowel only — it does not reach the whole colon (UCLH; Mayo Clinic). It needs less bowel preparation than a colonoscopy; at UCLH patients use an enema at home about two hours beforehand. Most people manage it without sedation, and gas and air can be offered. If something abnormal is found, a full colonoscopy may be recommended. Serious complications such as a tear in the bowel are rare.

England stopped using flexible sigmoidoscopy ("bowel scope") as a screening test after a 2020 recommendation from the UK National Screening Committee, and moved to the home FIT test instead (UK NSC).

4. Small-bowel capsule endoscopy

You swallow a capsule about the size of a large vitamin pill. It takes pictures as it passes through the small intestine, an area that ordinary scopes cannot easily reach (Mayo Clinic). Its most common use is looking for the source of bleeding in the small intestine, often after a gastroscopy and colonoscopy have not found the cause. No sedation is needed and you can usually move around during the recording.

A capsule can only take pictures: it cannot take a biopsy or treat anything, so a finding may need an enteroscopy to confirm or treat it (ESGE guideline, 2022). The main risk is the capsule getting stuck, which is more likely in people with a narrowing of the bowel. You should not have an MRI scan until the capsule has passed, and it is not done during pregnancy (St Mark's Hospital). SinoCareLink does not book small-bowel capsule endoscopy; this section is for information only.

5. Magnetically controlled capsule gastroscopy

This is a different kind of capsule, designed to look at the stomach. After drinking water, you swallow the capsule, and a doctor steers it around the stomach with an external magnet while the images appear on a screen. There is no tube and no sedation (NICE MIB104). Some systems can also go on to record the small bowel, but through SinoCareLink the magnetically controlled capsule is booked for the stomach only.

Studies, mostly from China, found that the capsule picked up most of the stomach lesions that a standard gastroscopy found. It cannot take a tissue sample or treat anything, so if something needs a closer look you would still need a conventional gastroscopy. It is not suitable for everyone — for example, people with a pacemaker, another implanted electronic device or implanted metal parts, or during pregnancy (NICE MIB104).

Through SinoCareLink, the magnetically controlled capsule is booked for the stomach only.

6. Enteroscopy (single- and double-balloon)

An enteroscopy uses a long scope fitted with balloons that help it move further into the small intestine than a standard gastroscopy can reach. It can go in through the mouth or through the bottom. Unlike a capsule, it can take biopsies and treat problems such as bleeding, polyps or narrowed sections, and it is often done after a capsule or other test has found something in the small bowel (Cleveland Clinic; Manchester University NHS FT).

It takes longer than a routine gastroscopy: Manchester University NHS FT tells patients the procedure itself takes 60 to 90 minutes, and Cleveland Clinic says it can take up to several hours depending on how far the scope goes and what treatment is needed. Sedation is used, although how deep it is varies between hospitals. SinoCareLink does not book enteroscopy; this section is for information only.

7. ERCP (endoscopic retrograde cholangiopancreatography)

ERCP combines an endoscope with X-ray pictures to reach the bile ducts and the pancreatic duct. Today it is mainly used to treat problems, such as removing stones from the bile duct or placing a stent. When only a diagnosis is needed, doctors usually choose tests with less risk, such as an MRCP scan or an endoscopic ultrasound (NIDDK).

ERCP carries more risk than a routine gastroscopy. Its particular risk is inflammation of the pancreas (pancreatitis): Guy's and St Thomas' tells patients that mild pancreatitis happens to about 5 in every 100 people who have an ERCP, and that some people get a more severe form (GSTT). It is usually done with sedation, sometimes under a general anaesthetic. SinoCareLink does not book ERCP; this section is for information only.

8. Endoscopic ultrasound (EUS)

EUS puts a small ultrasound probe on the tip of an endoscope. Because the probe sits close to the digestive wall, it can give detailed pictures of the digestive tract and of nearby organs such as the pancreas, bile ducts and lymph nodes, and a thin needle can take a sample if needed (Mayo Clinic; UCLH). Unlike ERCP, it is mainly used to look and to take samples; for bile-duct problems, Guy's and St Thomas' notes that EUS cannot remove stones or put in stents (GSTT). In the UK it is usually done with a throat spray and sedation. SinoCareLink does not book EUS; this section is for information only.

"Painless" endoscopy: sedation in China and the UK

In China, "无痛胃肠镜" (often translated as "painless" endoscopy) means the test is done under sedation given by an anaesthetist. This sedation is commonly based on propofol, an anaesthetic drug (national survey, China). In the UK, most endoscopies are done with a throat spray or with lighter sedation that leaves you relaxed but awake, and propofol is used less often and only by anaesthetists (British Society of Gastroenterology, 2023).

Propofol itself is not a painkiller, so it is commonly combined with other medicines, which may include opioid painkillers (propofol product information). If you have ever reacted to opioids, or have a soya or peanut allergy, tell us when you book so we can pass this on to the hospital before your appointment. The hospital's anaesthetist assesses you before sedation is given (at some hospitals, on the day itself) and decides what is suitable for you.

After sedation, do not drive, drink alcohol or sign important documents for 24 hours, and have someone with you; this is what UK guidance advises (BSG; NHS).

What SinoCareLink can arrange

• Sedated gastroscopy and colonoscopy — Standard US$400 or Premium US$500, with a bilingual companion on the day. This price covers the sedated examination only: if a biopsy or polyp removal is needed, the hospital charges for it separately (see the refundable deposit option on the product page).
• Magnetically controlled capsule gastroscopy — US$699, stomach only.

SinoCareLink is a medical-travel coordination service, not a hospital: the procedures are performed at a tertiary hospital or a licensed international medical centre in our partner network, confirmed with you before booking. If a biopsy is taken, pathology results are typically available within 5–7 business days. Small-bowel capsule endoscopy, enteroscopy, ERCP and EUS are described here for information only; we do not book them. For what a sedated gastroscopy and colonoscopy involves on the day, see our guide to painless GI endoscopy in China.

Frequently asked questions

Is a capsule as good as a gastroscopy?
Not as a replacement. Studies found that a magnetically controlled capsule picked up most of the stomach lesions a gastroscopy found, but it cannot take a biopsy or treat anything, so a conventional gastroscopy is still needed if something needs a closer look.

Will I be awake during the test?
It depends on the test and the country. In the UK many people are awake with a throat spray or light sedation. Sedated endoscopy booked through SinoCareLink in China uses anaesthetist-given sedation.

Can I drive after endoscopy?
Not for 24 hours if you have had sedation. Capsule tests do not need sedation.

Which of these tests do I need?
That depends on your symptoms and history, and your doctor decides. This guide explains what each test does; it is not a recommendation to have any of them.

Can SinoCareLink book an ERCP or an endoscopic ultrasound?
No. We book sedated gastroscopy and colonoscopy, and capsule gastroscopy of the stomach. The other tests in this guide are described for information only.

Ready to book, or have a question? See our sedated endoscopy options or contact us.