Colonoscopy is a modern endoscopic method of diagnosing diseases of the large intestine (from the rectum to the caecum) with an assessment of its condition using a long thin flexible probe – a fibrocolonoscope with a micro-camera at the end. During colonoscopy, the probe is inserted through the anus and progressively moves forward, which makes it possible to examine the walls of the colon throughout its entire length. At the same time, a careful supply of air is carried out, expanding the lumen of the intestinal tube and smoothing the folds of the intestinal walls. The fibrocolonoscope allows you to transmit an image of the mucosa to the monitor screen. With the help of colonoscopy, latent bleeding, inflammation, diverticula, tumors and other pathologies can be diagnosed, as well as, if necessary, perform a biopsy and remove polyps.
Endoscopic diagnosis of diseases of the large intestine due to its anatomical location has always presented certain difficulties. Until recently, the rectum was examined with rigid endoscopes to a depth of 30 cm. The date of birth of modern colonoscopy can be considered the middle of the twentieth century, when the first flexible fibrocolonoscopes with a controlled head were invented, allowing not only to examine the lumen of the large intestine and examine its mucosa, but also to photograph it. In addition, colonoscopy with a flexible fibrocolonoscope makes it possible to perform a biopsy of the affected area.
The advantages of modern colonoscopy in comparison with X–ray examination methods, including irrigoscopy, are obvious. Colonoscopy does not use a radiation component, it makes it possible to examine in detail the entire internal lumen of the large intestine with high-definition images, conduct therapeutic measures and record the entire manipulation process on a digital medium. In addition, colonoscopy is a method of early diagnosis of pathological changes in the intestine, simplifying the choice of optimal tactics for the treatment of a number of diseases.
Colonoscopy is divided into planned and emergency, as well as diagnostic, therapeutic and dynamic. Emergency colonoscopy is performed for intestinal bleeding, colonic obstruction (postoperative or acute), a foreign body in the large intestine. A planned study is indicated for chronic pain syndrome and irritable bowel syndrome (persistent diarrhea, constipation, flatulence, incomplete emptying syndrome). Colonoscopy is prescribed to identify the source of blood impurities in the feces, with iron deficiency anemia of unknown origin. The procedure is carried out with unexplained weight loss, suspected erosive colitis, polyps, with a positive blood test for cancer markers, X-ray or ultrasound indications for intestinal pathology (including oncological). In addition, colonoscopy is indicated in the presence of colon cancer and familial polyposis in close relatives.
Diagnostic allows the most accurate differentiation of inflammatory processes and tumors of the large intestine, to determine the prevalence of pathology, to carry out its morphological verification. In addition, colonoscopy is used to identify foci of endometriosis in the colon and to assess the state of the intestine in certain systemic diseases (collagenosis, amyloidosis, vasculitis). Dynamic is performed during dispensary observation of the patient. The aim of the study is to analyze the results of surgical intervention or conservative therapy in order to possibly adjust the treatment plan. Therapeutic is performed for excision of polyps, stopping bleeding, removal of a foreign body, recanalization of stenoses. In order to prevent colorectal cancer, recommended for all patients over the age of 45.
Сontraindicated for peritonitis, acute infectious process in the colon, anal fissures, thrombosed hemorrhoids, paraproctitis. Colonoscopy is not performed in patients with severe cardiovascular and respiratory insufficiency, in the acute period after stroke and myocardial infarction, with severe adhesive disease, ischemic or ulcerative colitis.
Preparation for colonoscopy
Colonoscopy requires careful preparation. In order for the diagnostic results to be as reliable as possible, there should be no fluid and feces in the lumen of the large intestine. 2-3 days before the colonoscopy, the patient is prescribed a slagless diet with the exception of fiber, legumes, black bread and cereals. In addition, the colon is cleaned using laxatives or a series of enemas. The cleaning procedure is carried out the night before or in the morning on the day of colonoscopy. Emergency colonoscopy for obstruction or bleeding does not involve preliminary preparation. The procedure is performed with a special fibrocolonoscope with optics irrigation. Planned colonoscopy is prescribed no earlier than 3-4 days from the moment of contrast examination of any parts of the gastrointestinal tract, after complete removal of barium suspension from the intestine.
Methodology of conducting
Colonoscopy is performed in stages, both with and without anesthesia. Severe pain syndrome is stopped by local anesthesia (dicaine). Anesthetic drugs are administered to children under 12 years of age or according to special indications and the patient’s desire during colonoscopy (except in cases of pulmonary heart failure and acute psychosis). In the case of an increased threshold of pain sensitivity, the patient is immersed in a superficial drug-induced sleep. Before a routine colonoscopy, antispastic agents are intramuscularly injected, which relax the muscles of the large intestine.
Colonoscopy is performed by an endoscopist surgeon in a hospital (department of coloproctology, gastroenterology) or a day hospital (outpatient), the duration of the procedure is about 30 minutes. Before the examination, the lower part of the trunk is completely exposed. Colonoscopy is performed on a diagnostic table or couch. The patient lies down on his left side and pulls his knees up to his chin. A fibrocolonoscope with a diameter of about 1 cm is inserted through the anus. At the same time, air is carefully supplied, straightening the folds of the intestine. Then the probe is gradually pushed forward. During a colonoscopy, in order to obtain the most complete information, the patient is asked to change the position.
At the moment when the colonoscope passes through the anatomical bends of the intestine, the patient may experience unpleasant sensations that disappear after removing the colonoscope from the lumen of the intestine. The image from the fibrocolonoscope is transmitted to a high-resolution monitor, which allows you to study in detail the condition of the walls of the colon. If necessary, during a colonoscopy, a biopsy of the lesion or a polypectomy is performed, a foreign body is removed – in such cases, the duration of the procedure increases. The course of colonoscopy is described in detail in the protocol. The conclusion is given to the patient’s hands. The diagnosis of colonoscopy is made on the basis of visual monitoring, biopsy results.
Colonoscopy can be complicated by a feeling of intestinal distension, pain spastic syndrome, which disappears when released from gases. An allergic reaction to medications prescribed in preparation for colonoscopy is possible. Very rarely there is bleeding, the mucous membrane is injured, the intestine is perforated. In this case, the colonoscopy is interrupted, an urgent consultation with the surgeon is carried out, if necessary, surgical intervention is performed. Prolonged fever, prolonged pain, rectal bleeding, vomiting, flatulence are the reason for medical consultation. The risk of complications during colonoscopy depends on the qualifications of the specialist.