Colonoscopy: the latest techniques and various types

By Cristiano Antonino On Jan 25, 2023

Colonoscopy is a diagnostic-therapeutic procedure that allows us to observe the colon and ileum (the end part of the small intestine, ed.) from the inside, then to diagnose any pathologies affecting the intestinal tract and, if necessary, also to intervene on these

A procedure that, performed in the traditional mode, can be unpleasant for the patient.

In order to make it less bothersome, over the past decades have been developed:

alternative or complementary types of colonoscopies (e.g., robotic colonoscopy, colonoscopy with video capsule, virtual colonoscopy…);
alternative bowel preparation modalities to classical (which some patients say can be more bothersome than the colonoscopy itself);

Types of colonoscopy

There are various colonoscopy techniques that are indicated and used by the gastroenterology specialist depending on the patient’s clinical picture.

Specifically, starting with the most recent ones, we talk about the following types of colonoscopy with alternative or complementary techniques of performing the procedure to the classical one:

robotic colonoscopy;
colonoscopy with videocapsule;
virtual colonoscopy;
traditional colonoscopy.

Let’s see what they are and how they work.

Robotic colonoscopy

Robotic colonoscopy is a state-of-the-art technique that involves the use of a flexible, disposable silicone colonoscope, which gently advances inside the intestine like a ‘caterpillar’ that stretches and shortens, without receiving any push from the outside.

Connected to a console, the physician conveniently maneuvers it via a joystick.

The advantages of robotic colonoscopy can be summarized as follows:

does not require sedation, except at the patient’s wish or for special circumstances, which makes the procedure particularly suitable for people who are unwilling or unable to undergo sedation, with the ability to return immediately to their daily activities, without having to remain under observation after the test is performed;
allows for biopsies and removal of polyps (polypectomies) up to 2 cm;
has no risk of infection, thanks to the sterile, single-use instrumentation;
excludes perforations, as the probe is made of soft silicone and adapts perfectly to the angles of the colon.

The disadvantages of the robotic procedure are that:

it is not indicated for major surgical operations, such as removal of polyps larger than 2 cm, for which, instead, use of the traditional technique is necessary;
narrow segments (stenosis) of the colon are not easily overcome by the probe, which has no possibility of external thrust.

The robotic procedure can, in any case, be safely converted in course to the standard one (under sedation, of course) so that the patient is always guaranteed complete exploration of the colon and therapeutic treatment.

Colonoscopy with videocapsule

Colonoscopy with videocapsule is a procedure performed orally through the ingestion of a small pill-shaped camera that, ingested like food, once it reaches the intestine allows images of the colon to be retrieved.

The advantages of colonoscopy with videocapsule are:

represents the simplest and least invasive procedure;
it does not require sedation; it can be performed by individuals who do not want or have problems performing it or who cannot perform the other colon exploration procedures.

The disadvantages of colonoscopy with videocapsule are:

the colon must have a very deep cleaning compared to traditional colonoscopy, or the test results are unreliable;
too fast transit of the capsule (less than 40 minutes) does not allow adequate exploration of the colon;
no sampling or surgical procedures can be performed so, if necessary, the patient will have to undergo a subsequent traditional colonoscopy (with repetition of bowel cleansing as well);
risk of capsule blockage in patients with, for example, intestinal strictures or advanced inflammatory disease, for whom this technique is not recommended.

Virtual colonoscopy

Virtual colonoscopy is a radiological investigation that, using computed tomography (CT) images, simulates a traditional colonoscopy on the computer, thus allowing the internal walls of the colon to be studied noninvasively, but only by inserting a small, flexible rectal probe into the bowel and insufflating carbon dioxide/air to distend it.

The advantages of virtual colonoscopy are:

is minimally invasive;
can be performed in cases of incomplete traditional colonoscopy (for long colon, lumen narrowing, etc.);
is indicated for elderly patients or those with contraindications to traditional colonoscopy such as, for example, subjects with heart disease or respiratory problems.

Disadvantages of virtual colonoscopy include:

its prescription must be evaluated by the referring specialist, especially in cases of pregnancy, as with all tests that involve exposure to radiation, even if low-dose;
has difficulty diagnosing flat lesions and polyps smaller than 5 mm in size;
cannot assess the inflammatory status of the mucosa;
it does not allow biopsy sampling or surgical procedures so that in case of dubious polyps or lesions, the patient will have to undergo traditional colonoscopy at different times with increased inconvenience for the user (who undergoes double preparation) and costs;
the procedure is safe, but exceptionally, perforations, rectal lesions, vagal (vagus nerve, ed.) reactions to colic distension may occur.

Traditional colonoscopy

Traditional colonoscopy is performed by inserting into the colon a thin, long tube equipped with a small camera (colonoscope), which allows a perfect view of the inside of the large intestine (colon), which is slightly inflated with air to allow exploration.

Traditional colonoscopy can take place:

limited to the first tract called the rectum (rectoscopy);
extended to the second intestinal tract, termed the sigma (rectosigmoidoscopy);
throughout the entire colon (pancolonoscopy), as is generally done and, where clinical indications exist, also the last tract (about 20 cm) of the small intestine (ileum) (pancolon-ileoscopy).

Traditional colonoscopy constitutes the ‘gold standard’ among colon exploration procedures both diagnostically and therapeutically.

It also allows for:

perform sampling and surgical procedures, such as removal of polyps (polypectomy) of different shapes and sizes using increasingly sophisticated techniques;
intervene on bleeding lesions;
treat neoplastic narrowings of the colon (by placing prostheses).

The disadvantages of traditional colonoscopy are:

it is an invasive procedure for which sedation (conscious or deep) is required to make the test less painful; sedation that is not always feasible or welcome by all patients and requires a short period of observation following the procedure. In addition, sedation can have, albeit limited, side effects/complications;
the risk, albeit very limited, of complications (bleeding, perforation) especially during therapeutic procedures;
may be difficult or incomplete in a particularly long colon or one with adhesions.

Preparation for colonoscopy

In order to perform a colonoscopy of any type and properly evaluate the inside of the intestine, it must be empty and well cleaned.

This is achieved by:

traditional preparations;
colon wash.

Traditional preparations

The standard colonoscopy preparation procedure provides for the patient:

specific diet to be followed in the 3-4 days before the test;
fasting for at least 6 hours prior to the service;
intake of liquid laxative preparations (in quantities generally 2 to 4 liters or 5 to 6 liters for those with major constipation) to cleanse the bowels. These ‘laxative drinks’ unfortunately often create discomfort, such as nausea and abdominal cramps, and, on the day of intake, prevent one from performing normal activities because one continually needs a toilet. Moreover, such preparations cannot always be taken and are sometimes contraindicated.

The Colon Wash

The colon wash or hydrocolon cleansing is a practice introduced by Dr. Cosentino in 2010 to ‘wash,’ as the English word ‘wash’ also indicates, the intestines in preparation for colonoscopy, as an alternative to the classic ‘laxative drink.’

Lasting about 45 minutes, with no discomfort, contraindications (if colon wash is indicated) or complications, at the end of the procedure colonoscopy can be performed immediately.

How it is performed

As with traditional preparation, colon wash equally requires:

fiber-free diet in the 3 days before the test;
intake of some mild laxative to soften the stool.

The patient, lying on his or her side or supine, has a cannula inserted into the rectum, connected to equipment that controls water pressure and temperature, equipped with a tube for entering clean water and one for removing fecal material along with the water used.

At the same time, the operator performs successive irrigations, massaging the abdomen to promote fragmentation and detachment of fecal materials.

Why is colonoscopy performed?

Colonoscopy is indicated in several conditions:

presence of obvious blood in the stool, a cause of possible intestinal bleeding (and not just hemorrhoidal disease);
positivity to the search for ‘occult blood’ in the stool;
weight loss without apparent cause;
iron deficiency anemia;
unexplained abdominal pain;
sudden constipation or prolonged diarrhea or alternating constipation and diarrhea;
prevention in individuals with ‘familiarity’ for colon cancer diseases.

This diagnostic modality, in the last 20 years, has taken on a fundamental role in the prevention of colorectal cancer: the most common cancer in Italy in total among men and women, almost always originating from benign tumors due to the proliferation of intestinal mucosal cells (adenomatous polyps) that take on average between 7 and 15 years to transform into malignant forms.

Polyps can be detected as they tend to bleed and protrude from the intestinal mucosa, so they are visible on its surface.

National screening involves fecal occult blood testing in individuals aged 50-70 years and in case of a positive result, colonoscopy, which also allows polyps to be removed.

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