Sigmoidoscopy is an endoscopic examination of the rectum and the lower part of the sigmoid colon using a special tube. The examination can be used for diagnostic or therapeutic purposes. Before sigmoidoscopy, a complete cleansing of the intestine is required. The procedure is performed after a preliminary finger examination of the rectum. It is performed without anesthesia, less often with the use of local or intravenous anesthesia. The patient is in the knee-elbow position or lying on his left side on a special table. During sigmoidoscopy, inflammatory, erosive, degenerative, infectious, and tumor processes are diagnosed. Assess the condition of internal hemorrhoids, identify cicatricial changes.
The study is carried out with a sigmoidoscope – a flexible tube that is equipped with a camera, a light source, as well as a mechanism for pumping air into the intestine and is connected to a monitor. The diameter of the tube is 2 cm, the length reaches 35 cm, which allows you to examine the mucous membrane of the large intestine for 15-30 cm from the anus. The design of the rectoscope makes it possible to take a biopsy, carry out therapeutic measures. Younger children are examined with a special small-sized rectoscope.
After 50 years, sigmoidoscopy is indicated as a preventive measure to detect colorectal cancer in the early stages of development. In addition, this study is prescribed to patients under the age of 50 who have a burdened heredity. In 2010, British specialists in the field of coloproctology conducted a large-scale study that showed that this preventive sigmoidoscopy can reduce the incidence of colorectal cancer in patients aged 50 to 65 years by 26-30% due to the timely removal of mini-neoplasms at the stage of asymptomatic pathology. For comparison: colorectal cancer, detected at the stage of the appearance of symptoms, can be completely cured in 10% of cases. This explains the relevance and prevalence of sigmoidoscopy at the present stage.
Patients are referred for research by doctors of different specialties: abdominal surgeons, gastroenterologists, oncologists, proctologists. Sigmoidoscopy is performed in an emergency or planned manner. A planned diagnostic technique is prescribed for abdominal pain of unknown origin, chronic constipation and diarrhea, pathological impurities in the feces, sudden weight loss. In emergency cases (heavy bleeding), the procedure is carried out according to vital indications. Sigmoidoscopy is effective in cases of suspected oncological lesion of the lower colon. Manipulation allows oncologists to determine the localization, shape, size and prevalence of neoplasia. Sometimes the study is used to assess the involvement of the large intestine in the oncological process with tumors of other localizations (in urology – with prostate cancer, in gynecology – with neoplasms of the female genital organs).
Surgeons use sigmoidoscopy to determine the cause of mucous and purulent discharge from the rectum, identify internal hemorrhoids, fistulas, abscesses, strictures, erosions, diverticula, single and multiple polyps. Gastroenterologists establish the etiology of disorders of the bowel emptying rhythm, diagnose inflammatory and infectious processes in the area of the distal colon. Pediatricians use this technique to confirm developmental abnormalities, inflammatory diseases and other pathologies. Sigmoidoscopy can be used for medical procedures, removal of polyps, sampling of material for histological examination, administration of medications.
Manipulation is contraindicated if the risk of its implementation exceeds the expediency of the appointment. The list of contraindications includes acute cerebrovascular accident, acute myocardial infarction, the general serious condition of the patient due to decompensated chronic diseases of internal organs, severe cardiovascular and pulmonary pathology with impaired respiratory function. The procedure is not performed with peritonitis, pronounced stricture of the anus and rectum. Relative contraindications to sigmoidoscopy are acute thrombosis of hemorrhoids, acute paraproctitis, painful bleeding anal fissures. With extreme caution, manipulation is carried out for pregnant women and children.
Diagnosis requires careful preparation. Detailed visualization of pathology presupposes complete preliminary cleansing of the intestine within 24-48 hours, since the presence of fecal masses in the intestinal lumen reduces the reliability of the study. Sigmoidoscopy is performed strictly on an empty stomach. On the eve of the procedure, products that cause increased gas formation are completely excluded from the diet, liquid food (broths, jellies, mineral water) is recommended, and it is advised to abandon products containing red food pigments that can mimic blood in the intestine during manipulation.
Further preparation for sigmoidoscopy is carried out at the discretion of the doctor – either with cleansing enemas on the eve and on the day of the study (no later than three hours before the procedure), or with laxatives inside, or 2-3 microclysms with a laxative effect half an hour before the manipulation. A combination of enemas and medications is possible. The preparation of the child for sigmoidoscopy is carried out according to a similar scheme. Before the study, the patient should warn the medical staff about pregnancy, chronic pulmonary-cardiac pathology, diabetes mellitus, allergies to medications, as well as about all medications taken.
Methodology of conducting
Sigmoidoscopy is performed on an outpatient basis, as well as during planned or emergency hospitalization in a hospital. Diagnostics is carried out in a specially equipped office by an endoscopist, who can be assisted by a certified nurse. The procedure is considered practically painless and is performed without anesthesia. In case of pathology of the anus, local anesthesia is performed or sedatives are pre-prescribed for oral administration. At the request of the patient, intravenous anesthesia is possible. Sigmoidoscopy is preceded by a finger examination of the rectum. During the manipulation, the patient is in the knee-elbow position or lies on his left side on the manipulation table, pulling his knees to his chest.
After lubricating the anus with vaseline, the rectoscope tube is inserted to a depth of 4-5 cm into the large intestine, air is insufflated through the endoscope into the intestinal cavity to straighten the folds of the mucosa. The process is carried out under visual control, the camera of the device takes pictures. Manipulations with the rectoscope can normally cause urge to defecate and unpleasant sensations. During the sigmoidoscopy, the patient may be asked to rise periodically to facilitate the advancement of the device. At a height of 12-14 cm, there is an anatomical transition of the rectum to the sigmoid. At the time of its passage by the rectoscope, maximum relaxation of the patient is required in order to avoid perforation of the intestinal wall. With severe soreness, manipulation is stopped.
During sigmoidoscopy, a specialist performs a detailed examination of the mucosa of the rectum and the lower part of the sigmoid colon. If necessary, it is possible to remove polyps, take a biopsy. Blood clots and mucus are removed by an electric pump. The procedure lasts about 20 minutes. Complications are unlikely, but intestinal injuries and bleeding are possible at the site of a removed polyp or a tissue section taken for biopsy. Perforation requires emergency surgical intervention. Without the use of sedatives, the patient leaves the medical facility by himself, when using them, he may need to be accompanied. During the day after sigmoidoscopy, bloating and pain may be observed, which pass on their own. If the pain does not subside, vomiting appears against the background of a rise in temperature and an admixture of blood in the feces, it is necessary to urgently consult a doctor. Normal bowel function is restored within a week.
Interpretation of results
In the absence of pathological changes, the results of the study are interpreted as the norm. In the presence of inflammation, erosions, tumor-like formations and other pathological processes, the endoscopist indicates their localization, nature and prevalence. If necessary, a second examination may be prescribed to clarify pathological changes, take a biopsy or remove a neoplasm. The conclusion on the results of the diagnostic procedure is received by the patient on the same day. If there are changes with the conclusion, it is necessary to contact the attending physician, who will prescribe treatment or additional studies to clarify the diagnosis. Histology results are usually prepared after 7-10 days, at which time the patient needs to come to an appointment to familiarize himself with the conclusion and determine the tactics of further treatment.