bowel health

Sigmoidoscopy

Sigmoidoscopy is a diagnostic test aimed at the visual exploration of the anus, rectum and the terminal tract of the colon, called sigma or sigmoid colon. Thanks to a flexible probe, inserted through the anal orifice and equipped with a camera and light source at its end, the doctor can appreciate the state of health of the mucosa on the monitor that covers these intestinal tracts internally. Moreover, during the sigmoidoscopy the operator has the possibility to remove polyps or abnormal tissue samples, useful for a subsequent microscopic examination and for therapeutic purposes.

Colorectal tumors

Colorectal cancer is the second leading cause of death in the Western world. Fortunately, if detected and treated in the early stages it is treatable in more than 90% of cases. Screening tests - such as the search for occult blood in stools, sigmoidoscopy and colonoscopy - guarantee a timely diagnosis, significantly reducing incidence and mortality. Even if the patient does not like him, colonoscopy and sigmoidoscopy allow him to fight:

  • early-stage tumors, diagnosing and treating them with less traumatic and more effective therapies;
  • tumors still confined to the polyp, diagnosing them and removing them during the examination without the need for surgery;
  • polyps that can turn into a malignant tumor, diagnosing and removing them as an outpatient during the examination, without the need for surgery;

These last two points are not satisfied by the virtual colonoscopy.

People who are reluctant to undergo sigmoidoscopy and / or colonoscopy should know that at an advanced stage, colorectal cancer causes the formation of secondary tumors (metastases) at the level of the abdominal organs, first of all the liver, making it necessary the partial or total removal of the affected intestinal tract and any metastases. This intervention, in addition to significantly worsen the patient's quality of life is not always decisive.

Sigmoidoscopy is therefore of enormous importance in the diagnosis and screening of colorectal cancer, revealing itself to be useful in the investigation of intestinal symptoms such as abdominal pains and cramps, rectal bleeding, constipation or chronic diarrhea, frequent alterations of the alvus (periods of constipation alternating with diarrheal episodes), iron deficiency anemia of unknown origin, tenesmus (feeling of incomplete stool evacuation), emission of ribbon-like excrement and abundant presence of mucus in the stool. For all these reasons sigmoidoscopy is in effect a simplified version of the most known, but also the most invasive, colonoscopy; this last diagnostic procedure, in fact, examines the entire large intestine, thus being more accurate but also more invasive and annoying for the patient; compared to sigmoidoscopy, it is also burdened by a higher rate of complications, which however remains very low (approximately 3 cases per thousand tests).

Statistically speaking, although the enteric traits examined by sigmoidoscopy represent less than half the overall length of the large intestine, they are home to approximately 60-70% of benign and malignant tumors. For this reason, numerous guidelines agree on the screening of colon cancer for the combined faecal sigmoidoscopy / search for blood, reserving the colonoscopic examination for the evaluation of positive cases. In particular, starting from the age of 50 it is recommended to perform a search for occult blood in the faeces every two years, while between 58 and 60 it is important to undergo a rectosigmoidoscopy to be repeated then every decade. However, in the presence of familiarity with the disease, these screening tests can be recommended already at an early age and more frequently.

Alternative names: rectosigmoidoscopy, proctosigmoidoscopy; the flexible adjective refers to the probe used, which before the advent of microtechnologies was rigid, without a camera and based on "Spartan" procedures and tools, very similar to those described in the article dedicated to rectoscopy.

Is sigmoidoscopy painful? How do you perform and how do you prepare for the exam?

The sigmoidoscope, with a diameter of about one centimeter, is gently inserted through the anus, after adequate lubrication and digital inspection. During the examination the patient lies on his side, usually the left one, with the knees flexed towards the chest; normally the procedure does not cause significant pain and therefore does not require the use of pain medication; the use of sedatives may however be necessary in the face of a particularly anxious patient. During the examination it is possible to feel pressure sensations, air movements and evacuative stimuli; in fact, through the sigmoidoscope, the doctor proceeds to blow in carbon dioxide to relax the intestinal walls and get a better overview of them. This operation is also responsible for transient phenomena of meteorism and abdominal cramps that occur at the end of the investigation.

Sigmoidoscopy lasts an average of 10-20 minutes and there is usually no need for anesthesia or sedation. If this is necessary, the doctor can ask the patient to stay in the hospital for an hour or more, in order to "dispose of" the effect of the drug; at the same time it will advise against driving, recommending rest for the rest of the day.

The "standard" preparation for sigmoidoscopy consists in performing a single or double evacuative enema at home two hours before the procedure. This operation is necessary to clean the walls of the final part of the intestine, thus preventing faecal residues from hiding the underlying mucosa. The methods of preparation are suggested by the digestive endoscopy center and can vary from a clinic to an outpatient clinic; instead of enema, for example, a liquid diet can be prescribed in the 12-24 hours preceding the appointment, assisted by a laxative to be taken the previous evening or the following morning if the appointment is fixed in the afternoon (in these cases the preparation for sigmoidoscopy approaches that described for colonoscopy).