Endoscopy

What is it?

According to MedlinePlus: endoscopy is "a way of looking inside the body using a flexible tube with a tiny camera and light on the end", this tool is called an endoscope, and it is inserted through a natural opening in the body or a small cut. According to the NHS the endoscope carries a camera and instruments at its tip, and is used to check for problems inside the body or treat them.

According to MedlinePlus there are many types of endoscope named for the organs or areas they examine: anoscopy for the inside of the anus; colonoscopy for the inside of the colon (large intestine) and rectum; enteroscopy of the small intestine; endoscopic retrograde cholangiopancreatography (ERCP) for the small ducts that drain the gallbladder, liver and pancreas; sigmoidoscopy for the lower part of the colon and rectum; upper endoscopy (EGD) for the oesophagus, stomach and first part of the small intestine (the duodenum); bronchoscopy to look at the airways (the trachea) and lungs; cystoscopy for the inside of the bladder; laparoscopy to look directly at the ovaries, appendix or other abdominal organs; and arthroscopy to look inside joints such as the knee. The NHS also mentions colposcopy and hysteroscopy.

According to NIDDK: upper endoscopy is also called oesophagogastroduodenoscopy (EGD), in which the doctor sees the lining of the upper digestive tract. Colonoscopy is a procedure in which the doctor uses a flexible tube with a camera (a colonoscope) to look inside the rectum and colon.

Why is it done?

According to the NHS endoscopy may be performed to try to find the cause of symptoms such as stomach pain, indigestion, difficulty swallowing or internal bleeding, to take a small sample of cells (a biopsy) to examine for a condition such as cancer, and to treat problems such as bleeding or remove small growths such as polyps or fibroids.

Upper endoscopy according to NIDDK: to find the cause of unexplained symptoms such as persistent pain, heartburn, vomiting or swallowing problems; to detect diseases such as gastro-oesophageal reflux disease, coeliac disease, cancer and Barrett's oesophagus; to remove polyps or other growths; to treat bleeding from ulcers and other conditions; and to carry out some weight-loss procedures. In its reflux diagnosis page NIDDK states that the doctor may request it to check for complications of reflux or for other problems that may be causing the symptoms.

Colonoscopy according to NIDDK and MedlinePlus: to find the cause of rectal bleeding, a change in bowel habit such as diarrhoea, abdominal pain or unexplained weight loss; to follow up polyps or changes seen on other tests or to monitor a previous colon cancer; anaemia due to iron deficiency (usually when there is no other cause); blood in the stool or black tarry stools; and inflammatory bowel diseases (ulcerative colitis and Crohn's disease). It is used as a tool for screening for colon polyps and colorectal cancer; NIDDK states that (US) guidelines recommend starting screening at age 45 for those with no health problems or risk factors. Screening ages and intervals differ between countries, and the doctor decides what suits you.

In irritable bowel syndrome NIDDK states that the doctor may request colonoscopy to check for conditions such as colon cancer or inflammatory bowel disease, or an upper endoscopy with biopsy to check for coeliac disease, depending on the results of blood or stool tests, a family history of digestive diseases, and the presence of symptoms that may indicate another condition.

Preparation

According to MedlinePlus preparation differs by type of endoscopy: anoscopy needs no preparation, whereas colonoscopy needs a special diet and laxatives; so follow your care provider's instructions. According to the NHS you may need to refrain from eating and drinking for several hours beforehand, or take certain medicines such as laxatives or antibiotics, or stop certain medicines such as blood thinners, and only according to the medical team's instructions.

For upper endoscopy according to NIDDK: refrain from eating and drinking for up to 8 hours before the procedure. Discuss with the doctor all prescription and non-prescription medicines, vitamins and supplements you take, including aspirin, arthritis, diabetes or blood pressure medicines, blood thinners, iron supplements and non-steroidal anti-inflammatory drugs. Arrange for someone to take you home, as sedatives or anaesthesia need time for their effect to wear off before you drive.

For colonoscopy according to NIDDK and MedlinePlus: the bowel must be completely empty and clean. You may be asked to avoid high-fibre foods and follow a clear-liquid diet (such as water, fat-free broth and fruit juice without pulp) for a day or more, and MedlinePlus mentions drinking plenty of clear fluids for 1 to 3 days before the test. A bowel-cleansing preparation is then used (laxatives as pills, liquid or powder, or enemas), which causes diarrhoea so stay near a bathroom. MedlinePlus states that the care provider may ask you to stop some blood thinners or iron tablets days before the test (as iron makes stools black), and stresses not stopping any medicine without consulting your care provider.

How is it done?

According to the NHS you are usually awake during endoscopy, and may be given a local anaesthetic to numb the area or a sedative to help you relax. It may be uncomfortable, and takes between 10 minutes and an hour. According to MedlinePlus all of these tests may cause discomfort or pain, and some are done after giving sedatives and pain relievers; so ask your care provider what to expect.

Upper endoscopy according to NIDDK: performed by a doctor in a hospital or outpatient centre. An intravenous line is placed in the arm or hand, you are often given a sedative or a medicine to help you relax, and you may be given a liquid to gargle or a spray to numb the throat. You lie on your side, and the doctor carefully passes the endoscope through the oesophagus into the stomach and duodenum, may inflate air to ease the view, and may take small tissue samples with small forceps through the scope. It usually takes 10 to 20 minutes.

Colonoscopy according to NIDDK and MedlinePlus: performed in a hospital or outpatient centre, and mostly by a trained doctor called a gastroenterologist. A sedative, anaesthetic or pain reliever is given through a vein, you lie on your left side with your knees bent towards your chest, and the scope is gently inserted through the anus into the rectum and colon, air or carbon dioxide is inflated to improve visibility, and the more detailed examination is done while the scope is withdrawn. The doctor may remove polyps and send them to the laboratory, and you will not feel their removal according to NIDDK. It usually takes under an hour. According to MedlinePlus you may feel no discomfort or not remember the test because of the sedative, and you may feel pressure or brief cramps and gas when air is inflated.

Understanding the result

According to MedlinePlus (colonoscopy): a normal result is healthy bowel tissue. Abnormal results may indicate: abnormal pouches in the lining of the bowel (diverticular disease), areas of bleeding, cancer of the colon or rectum, colitis due to Crohn's disease, ulcerative colitis, infection or reduced blood supply, or small growths (polyps) in the lining of the colon. This is a list of possibilities mentioned in the source and is not a diagnosis; what applies is the procedure report and your doctor's interpretation.

According to the NHS the doctor or nurse may explain the results before you leave hospital, whereas biopsy results usually arrive by letter or phone call within a few weeks. According to NIDDK a pathologist examines the samples, and results may take a few days or more.

Risks and side effects

According to MedlinePlus each type of endoscopy has its own risks, which the care provider explains before the procedure.

Upper endoscopy according to NIDDK: the risks are low, and may include a reaction to the sedative involving breathing or heart problems, perforation (a hole) in the lining of the upper digestive tract, and bleeding which is usually minor and stops without treatment. Bloating, nausea or a sore throat may occur afterwards for a short time.

Colonoscopy according to NIDDK: risks include bleeding, perforation of the colon, a reaction to the sedative involving breathing or heart problems, and severe abdominal pain; perforation occurs in about 3 in every 10,000 procedures, and bleeding in about 15 in every 10,000 procedures. MedlinePlus lists: severe or persistent bleeding after a biopsy or polyp removal, a hole or tear in the colon wall that may need surgery to repair, infection needing antibiotic treatment (very rare), and a reaction to the relaxing medicine causing breathing problems or low blood pressure.

Limits of the test

The source pages did not mention general limits of endoscopy accuracy. NIDDK states that biopsy samples are examined by a pathologist before the result is issued, and that in irritable bowel syndrome the doctor chooses tests according to the condition. This page does not cover the details of virtual colonoscopy, which NIDDK mentions among screening options, nor bronchoscopy, cystoscopy or arthroscopy.

After the test

After upper endoscopy according to NIDDK: the sedative needs time for its effect to wear off, and you stay at the hospital or centre for about an hour, and some people may need to stay overnight. You will not be able to drive after the procedure, so you need someone to take you home.

After colonoscopy according to NIDDK: you stay for about 30 to 60 minutes, and you may feel cramps or bloating in the first hour, and full recovery and a return to your usual food is expected the next day. If polyps were removed or a biopsy taken there may be slight rectal bleeding, which is normal. According to MedlinePlus you usually leave after about an hour, and are advised to drink plenty of fluids and eat a healthy meal, and avoid driving, operating machinery, drinking alcohol and making important decisions for at least 24 hours, and you can return to your usual activity the next day.

According to the NHS you usually stay about an hour to recover, and if you had a sedative do not drive for 24 hours, and someone must stay with you through the night and during the first 24 hours.

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