Why do I have to drink this preparation?

The bowel preparation for a colonoscopy is important to complete because unless the bowel is clear of faecal matter, the test may not be accurate. It is important that all the preparation is finished as per instructions to clear out the furthest part of the bowel.

What do I do if I vomit during preparation?

If vomiting occurs during the preparation phase, please ring MercyAscot Endoscopy during office hours as soon as possible and check with nursing staff whether anything further needs to be done. You may need to come into the clinic for further preparation earlier than your booked time. Ginger is a natural anti-nausea product and some patients find ginger ale is beneficial if nauseated.

When should I take my normal medications?

MercyAscot  staff will advise patients on what medications should be stopped before the procedure. Because biopsies are often taken, drugs that may promote bleeding (e.g. Warfarin, Dabigantrin, Clopidogrel etc) usually need to be stopped some days before the procedure. Aspirin or Cartia does not need to be stopped. Please check with staff for instructions. All normal medications can be taken four hours before starting bowel preparation or four hours after finishing bowel preparation to allow for absorption. Patients taking oral contraceptives need to be aware that the efficacy cannot be guaranteed due to bowel preparation.

What does 'clear fluids' mean?

Clear fluids are anything that can be seen through, i.e. not opaque or cloudy. This does not necessarily mean no colour but highly coloured fluids should be avoided. Examples of clear fluids include: strained chicken noodle soup, black tea, Gatorade, lemonade, ginger ale etc. A more comprehensive list is included on the instruction sheet.

Safety and risks

The endoscope is completely cleaned and disinfected between each patient to avoid the risk of transmission of serious diseases such as HIV or hepatitis. There is a small risk of teeth being damaged during a gastroscopy procedure.

Serious complications of gastroscopy and colonoscopy are rare, at less than 1 in 10,000 examinations for gastroscopy and 1 in 3,000 for colonoscopy. However complications can occur and include the following:

  • Gastroscopy and colonoscopy are considered to be very accurate tests. However, there is a risk that an abnormality may not be detected
  • Intolerance to the bowel preparation for colonoscopy. Some people develop dizziness, headaches or vomiting
  • Reaction to the sedative. This is very uncommon but is especially of concern in people who have severe heart disease or lung disease
  • Perforation (making a hole in the bowel or upper gastrointestinal tract wall)
  • Significant bleeding.

It is possible if these serious complications occur that you may require surgery or a blood transfusion.

Rare side effects can occur with any procedure. Death is extremely rare.

If you wish to have further details please discuss this with your endoscopist before the procedure.

If you have any of the following symptoms in the hours or days after your procedure you should contact MercyAscot or your doctor's rooms immediately: severe abdominal pain, black tarry motions, persistent bleeding, fever or other symptoms that cause you concern.


The aim of "conscious sedation" is to reduce anxiety, reduce awareness and reduce potential discomfort caused by air being pumped into the bowel. It is not an anaesthetic that is administered.

Is the procedure uncomfortable?

Each patient has a different experience. The majority of patients do not recall much of their endoscopy.

Patients undergoing colonoscopy sometimes experience a feeling of wind pain or cramp as the endoscope goes around the corners in the bowel. This discomfort is not for the duration of the colonoscopy. It is very important following a colonoscopy to pass the wind that may be trapped in the bowel.

A gastroscopy is not painful. Some patients experience a feeling of being bloated.

Post procedure diet and activity

You will be at MercyAscot for up to two hours. When you are ready for discharge, you will be walking and talking but may feel a bit "sluggish". It may be sensible to go home and put your feet up for a few hours. Do not have alcohol on the day of the procedure. It is recommended that you have someone stay with you the night after your procedure.

Following a gastroscopy, you can consume normal diet and fluids after discharge. If you have had a local anaesthetic throat spray, be a bit careful with the temperature of food and fluids for the first two hours as the throat spray does not wear off fully until then.

Following colonoscopy, it is important to drink plenty of fluids as the bowel preparation has a tendency to dehydrate the body. You can resume a normal diet immediately following discharge.

If a sedative has been administered, you may not drive on the day of the procedure. Also, do not operate machinery or make important decisions that day. On the day after the procedure you may resume all normal activity.