Reactions to the anaesthetic. Reactions such as anaphylaxis to medications used for anaesthetics are very rare and you will be treated immediately by your anaesthetist. Depending on your allergic reaction, your operation may be cancelled in the interests of your overall health. 

Heart attack / stroke. Anaesthetics and the physiological stress of an operation increases the strain on your heart. These are rare complications, and usually related to underlying heart diseases. 

Breathing difficulties. General anaesthetic is designed to relax your muscles including those responsible for your breathing. These issues are rare and temporary. Risks are usually related to underlying lung and heart conditions. 

Being semiconscious. This is related to individual tolerance to anaesthetics and is very rare.  

Aspiration. Food content may come up from your stomach and go down into your lung. This is the reason we ask you to fast before an operation. 

Nerve injury. A nerve may be temporarily compressed during your operation because you are not awake to reposition yourself. This is rare and temporary, however, recovery may take up to many weeks depending on the nerve involved and the duration of the operation.

Minor damage to mouth/teeth. This is due to the breathing tube being placed in your mouth which may cause irritation after the procedure. 

Hoarse voice. The breathing tube reaches all the way down your throat and may cause a bit of irritation leading to a hoarse voice. You can expect to fully recover from this irritation. 

Temporary vision changes. All care is taken to protect the eyes because you will be unable to close your own eyes under a general anaesthetic. Eye ointments are often used and may cause blurriness on waking. 

Cognitive changes. Anaesthetics affects the brain and can cause confusion and memory loss. Older people, particularly anyone with underlying dementia are more likely affected. 

Bleeding. Any operation carries the risk of bleeding because cuts need to be made in the operation. Bleeding is usually minor and stopped during the operation. 1 in 1000 people may need a blood transfusion. 

Infection. Any time a cut is made, there is a risk of infection. Infection risks depend on the reason for the operation. Clearly the risk of infection is higher if the operation performed is to treat an infection. Overall infections rates for elective operations are around 1-2%. 

Bowel injury. Laparoscopy involves inserting instruments into the abdomen. All care is taken to avoid injury, and injuries to organs inside the abdomen are rare, with an over all risk of around 3 in 1000. 

Hernia. Even tiny key-hole cuts disrupt the strength of your abdominal wall under the skin. These weaknesses are potential points for hernias to occur where contents inside the abdomen come out through these incision sites. Healing takes about 6 weeks, and that is the reason we ask you to perform light duties during this period. 

Bleeding. This may occur if we take biopsies or remove polyps. The risks of bleeding is generally low, but is higher if you take medications for anticoagulation (blood thinners). 

Bowel Perforation (hole in the bowel). This is very rare, but if it happens you may need an operation to fix or remove the area affected. 

Missed lesions. Sometimes it is not possible to see every aspect of the large bowel. This is often due to inadequate bowel preparation and having poo covering parts of the bowel. We always try to clean the bowel wall when we are looking but this is not always possible and small lesions may be missed.