Colonoscopy is one of the endoscopic examination methods. Endoscopic examinations are done by a tool called an endoscope. It is a tube of varying lengths, which is inserted inside hollow organs or body cavities. A small camera is built in on one end, which is used to capture the image of the organs's mucous membranes, which is then displayed on a screen observed by the operator. The other end is used to control the endoscope. An internal channel, used to insert tools as needed is also a part of the endoscope. Endoscopes are adjusted based on the organs examined by them, which is also the basis for the names of the different examinations, such as gastroscopy for the examination of the esophagus and the stomach, colonoscopy for the larger intestine, bronchoscopy for the bronchi, cystoscopy for the urinary bladder etc.
Preparations for colonoscopy
It is necessary for colonoscopic examination for the intestine to be properly prepared, which is to say it must be emptied. Remains of feces can complicated the examination by obstructing the visibility of the mucous membranes of the intestine. To empty the intestine, the patient is required to follow a low residue diet for 2 days before the examination. This diet doesn't cause flatulence, is easily digestible and contains foods which do not leave indigestible remnants and do not irritate the bowels. A day before the exam, the patient is required to drink laxative solutions, such as Fortrans. You need to expect bowel movements during the day and as such it is advised to stay at home.
The process of colonoscopy
The examination itself is performed by a specialized doctor – a gastroenterologist. The examination is done lying on your left side, with the doctor inserting the endoscope through the anus, to the final part of the larger intestine. For better visibility of the intestine, air needs to be blown (insufflated) into the bowel, leading to a feeling of uncomfortable pressure. This feeling is entirely individual, as every person has a different threshold of pain. An anesthesiologist is present during the examination as well, applying painkillers intravenously before the examination, as well as sedating the patient in such a way that he remains conscious. This is because sometimes it may be necessary to change positions during the exam. The sleepiness and sedation persist even after the exam, so patients remain in the bed, usually in the next room, up to 2 hours after. It is also advisable to bring someone to accompany you to the hospital. The patient should not drive any motor vehicles for 24 hours after the procedure. In certain cases, the patient may be fully sedated by the anesthetist, similarly to a surgery. This is used only exceptionally, reserved to hard to examine patients or children. If necessary, it is possible to take tissue samples, which are sent to biopsy. If the doctor finds any polyps, those can be immediately, painlessly removed. The exam can take anywhere between 15 minutes and an hour. The result is know immediately after the end.
An indication is a circumstance requiring a diagnostic procedure or a treatment. The reasons for colonoscopy may be various, such as intestinal bleeding, bleeding revealed in an occult blood stool testing, unexplained anemia, long-term diarrhoea with unknown causes, Crohn's disease or ulcerous colitis, intestinal inflammations of different causes, tumors of the larger intestine and persons with large risks of intestinal tumors.
A contraindication is a circumstance which directly prevents certain examinations or treatments. In the case of colonoscopy these are serious heart conditions, a state of shock, acute abdomen, high-risk or advanced pregnancy. Colonoscopy is also not performed in acute colitis, such as Crohn's disease and ulcerous colitis. It's also not advised to perform this exam up to 3 weeks after an intestinal surgery, pulmonary embolism and aortic aneurysm.
Complications associated with other endoscopic examinations can appear even after colonoscopy. These are allergic reactions to the applied drugs, heart and respiratory difficulties or infections. A possible complication is also a rupture, perforation of the larger intestine. This is generally caused by an overly large pressure applied by the operator during the insertion. Bleeding can also by caused by the removal of polyps, less commonly by taking tissue samples.