Colonoscopy

Colonoscopy is a diagnostic procedure aimed at direct vision of the internal walls of the large intestine (in particular the colon).

execution

During the examination a small flexible probe called a colonoscope is used, equipped at the apex of a camera and light source.

This specially lubricated probe is inserted into the anus and slowly ascended into the rectum and other tracts of the large intestine, meeting in the order sigma, descending colon, transverse colon, ascending and blind colon (see figure below); having reached the last section of the small intestine, called the ileum, the colonoscope is withdrawn with equal delicacy.

Thanks to the camera, during the colonoscopy the doctor can appreciate the state of health of the colon by observing the images transmitted by the instrument to the appropriate screen.

In order to guarantee a better visualization of the colic mucosa, distension of the intestinal walls is required during colonoscopy, which is obtained by blowing carbon dioxide through the colonoscope. This can cause some discomfort to the patient.

During the entire operation the patient remains lying on his left side, but may be asked by the doctor to perform small movements.

Painkillers and tranquilizers are generally administered before beginning a colonoscopy, to make the examination more comfortable and to reduce unpleasant sensations.

Overall, the investigation continues for about 30-40 minutes.

What is it for?

The main application of colonoscopy lies in the investigation of the state of health of the colonic mucosa, in order to identify any lesions, ulcerations, occlusions, tumors or polyps.

Interventional colonoscopy

In addition to acting as a video camera and blowing air, the colonoscope can - if necessary - clean the walls of the colon with water, aspirate the intestinal contents or act as a vehicle for surgical instruments with which to take tissue or remove polyps .

Therefore, colonoscopy has not exclusively diagnostic purposes, but can also be used to perform biopsies and therapeutic interventions. In this case we speak of interventional colonoscopy.

Insights on Colonoscopy

Directions Is colonoscopy painful? Risks and side effectsContraindicationsAfter colonoscopy Preparation for colonoscopy Diet and preparation for colonoscopy Diet after colonoscopy Virtual colonoscopy Rectoscopy Sigmoidoscopy Polypectomy Colonoscopy and herbal medicine

Indications

Colonoscopy essentially recognizes two large fields of application: colon cancer screening and the search for diagnostic elements in the presence of intestinal signs and symptoms.

COLONSCOPIA AND CANCER AT COLON

The examination can be performed as a first or second level investigation for colon cancer screening. For the population without major risk factors beyond age, the guidelines recommend performing a colonoscopy or a sigmoidoscopy between the ages of 58 and 60, to be repeated every decade. The two tests are based on the same methodological principles, with the difference that the sigmoidoscopy is limited to the endoscopic study of the last part of the colon; its main disadvantage is the fact that slightly less than half of adenomatous polyps and tumors form in the upper tracts, while on the other hand it exhibits the important advantage of being less invasive than and exposing the patient to a lower degree of risk. Colonoscopy, on the other hand, while being considered the "gold standard" for colon cancer screening, requires a more troublesome preparation, a longer execution time and presents a greater risk of negative side effects (such as intestinal perforation and bleeding), which can occur in 2-3 cases per 1000 exams. For this reason, in people with medium-low risk, colonoscopy is mainly applied as a second-level investigation after the occurrence of occult blood in the faeces or polyps by sigmoidoscopy.

In the presence of other risk factors, such as polyposis of the colon or familiarity with this and other cancers, the doctor may recommend performing a colonoscopy as a first-level investigation starting at the age of 40/50 every five or ten years.

COLONSCOPY AND DIAGNOSIS OF INTESTINAL DISEASES

In addition to colorectal cancer screening, colonoscopy is typically used to investigate the origins of symptoms such as abdominal pain, rectal bleeding, constipation or chronic diarrhea, frequent alterations of the alvus (periods of constipation alternating with diarrheal episodes), anemia iron deficiency of unknown origin, tenesmus (feeling of incomplete stool evacuation), emission of ribbon-like excrement and abundant presence of mucus in the faeces. Many of these symptoms are also attributable to the cancerous forms of colorectal cancer.

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Is colonoscopy painful?

Although many people are reluctant to the idea, especially due to the embarrassment associated with the particular diagnostic procedure, colonoscopy is usually well tolerated. Even if the examination is undoubtedly very annoying, the action of the painkiller and the tranquilizer, in general, succeeds in attenuating the unpleasant sensations. When the colonoscope is moved or used to blow air, the patient can feel slight abdominal cramps or an urge to evacuate; any biopsies are generally painless. The "annoyance" of the exam is however largely influenced by the skill of the operator and the anatomy of the colon.

All these problems are overcome through an alternative technique that is only slightly less effective than the standard procedure. We are talking about virtual colonoscopy, which unlike the previous one does not require the insertion of the probe and the use of sedatives to calm the pain, since it uses a special radiological equipment kept outside the patient. Despite this, the virtual colonoscopy has the big limitation of not being able to intervene with biopsies or excisions of any polyps found.

Risks and Side Effects

Colonoscopy is a low-risk diagnostic test; Important complications occur statistically in about 3 cases out of 1, 000, and can be caused by:

sedatives used during the exam,
accidental perforation of the colon
possible bleeding following the removal of polyps or other abnormal tissues.

Among these, the most serious complication (<1 case in 2, 000) is colon perforation, which requires immediate major surgery.

Any blood loss can instead be stopped by cauterization already during colonoscopy, which must be repeated for this purpose if the bleeding occurs without spontaneous arrest in the days following the first examination.

The other complications concern the effect of sedative drugs on people at risk, such as heart patients.

Contraindications

Colonoscopy is not recommended in the case of acute diverticulitis, toxic megacolon and recovery from surgery in this section of the intestine, due to the increased susceptibility to the risk of intestinal perforation.

After the Colonoscopy

At the end of the colonoscopy, 30 to 120 minutes of hospitalization may be requested, so that the effect of the sedatives used is reduced; also for this reason it is generally recommended to go to the appointment with an assistant and to rest for the rest of the day (the drugs used could cause drowsiness and exhaustion; driving a vehicle is therefore strongly discouraged, as well as involvement in other activities that require careful supervision).

Flatulence and meteorism are common problems at the end of the exam, due to the air blown during colonoscopy. As for the diet, during the rest of the day preference will be given to light and easily digested foods.

Although - especially in patients undergoing biopsy or polypectomy - a slight loss of blood from the anus in conjunction with the first defecation following colonoscopy is quite normal, repeated blood loss justifies the immediate medical consultation. The same is true if in the following days abdominal pain or high fever should appear.