Bowel Screening

Side effects of colonoscopy

For most people a colonoscopy is straightforward, without serious side effects or complications. The sedative takes time to wear off, so people usually rest for a while before going home. People are usually pretty hungry after not eating the day before and are grateful for a cup of tea and a biscuit or a sandwich. People who have been sedated are not allowed to drive home themselves. The hospital will arrange transport for those who cannot get a lift from family or friends. Many said they had had no side effects after the colonoscopy apart from feeling a bit sleepy.

After his colonoscopy one man thought that there might have been a problem with his oxygen levels because an alarm sounded twice. He was told to take some deep breaths and soon felt better. Apart from that he made an uneventful recovery.

Some people had been quite hungry when they got home. One man wanted fish and chips and another described the bacon and eggs and ham sandwiches that his wife made for him. He saw a trace of blood in his stools, but had been told to expect this because he had had polyps removed. The doctor told him to inform the hospital if bleeding became continuous or heavy.

Many people appreciated the phone calls they received from the nurses after they got home. The nurses or other members of the team phoned to make sure people had recovered from the colonoscopy without serious side effects.

During a colonoscopy people may react to the sedative and have temporary breathing or heart problems. The removal of polyps or tissue samples can cause heavy bleeding - this happens in about one in every 150 colonoscopies. A rarer complication is perforation of the bowel wall by the colonoscope. The chance of this happening are about one in 1,500. If this happens the person may need an operation to mend the hole. Even more rarely the procedure can lead to death. Current evidence suggests that this may happen in around one out of every 10,000 procedures (statistics from ‘The Colonoscopy investigation’ leaflet from the NHS Cancer Screening Programmes February 2015).

None of the people we interviewed had one of these serious complications, but some said they felt a 'bit shaken' after the colonoscopy and had experienced side effects that they found distressing. Wind or cramping pains caused problems for some.

One man had had violent pains at the base of his stomach, which he assumed were due to wind, and then two days after the colonoscopy he had diarrhoea.

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Another man remembered that soon after he got home he felt cold and he developed uncontrollable shaking. He had headaches, he had cramp in his stomach and he had a 'terrible sensation' that his bladder was very badly bruised.

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One woman had had very bad wind pain after the colonoscopy. The next day she went to the supermarket with her husband and suddenly felt faint. She recalled that she had been told to relax and not to sign any legal documents for 48 hours after the colonoscopy and thought she might have been foolish to go out.

Most people took two or three days off work, a day to prepare for the colonoscopy, a day to have the procedure and a day to recover, but a bus driver felt that he needed a bit longer.

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Last reviewed May 2016.
Last updated May 2016.


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