Sigmoscopy

Sigmoidoscopy, sigmoidoscopy or rectosigmoscopy is an instrumental method of examining the end part of the main part of the large intestine, the sigmoid colon (colon sigmoideum), which passes directly into the rectum.

What is this procedure? This procedure is diagnostic: with its help, gastroenterologists and coloproctologists diagnose intestinal diseases by examining the mucous membrane lining the sigmoid and rectum from the inside with a fiber-optic endoscopic apparatus (sigmoidoscope). 

Indications for the procedure

Complaints of frequent pain in the abdomen, in the left side, in the iliac and / or groin area; bloating and heaviness in the abdominal cavity; constipation or diarrhea (indicating disturbances in intestinal motility); the presence of bouts of vomiting with bile or the presence of an admixture of blood in the feces are indications for sigmoidoscopy - to determine the cause of the pathology. 

This examination of the  sigmoid colon  helps the doctor identify or confirm:

• chronic non-ulcer colitis of the  segmental type in the form of inflammation of the sigmoid colon (sigmoiditis) or inflammation of the sigmoid and rectum (proctosigmoiditis);
• ulcerative colitis and Crohn's disease;
• adenocarcinoma of the sigmoid colon ; [1]
• anatomical anomaly in the form of  dolichosigma ;
• colon polyps and  diverticula .

Sigmoscopy is used as one of the  methods for diagnosing hemorrhoids  and a method for screening colorectal cancer -  rectal adenocarcinoma .

In addition, sigmoidoscopy is used to take a sample of the intestinal wall tissue (biopsy), for endoscopic surgery on the large intestine (for example, to remove polyps), as well as for emergency care in cases of volvulus of the sigmoid colon (a form of acute intestinal obstruction) - for its endoscopic detorsion. [2]

When using such endoscopic examination methods as sigmoidoscopy and sigmoidoscopy, the differences are that  sigmoidoscopy  (or rectoscopy) allows visualization of the inner surface of the rectum (rectum) and only a small part of the sigmoid rectal sphincter passing into it, which is curved into the shape of the Greek sigma letter (similar to "s"). Further, the rectoscope tube is not inserted, and only sigmoidoscopy with a flexible endoscope allows visualization of the sigmoid colon along its entire length - up to the descending colon (colon descendens) and the distal sphincter. 

Preparation

Before any endoscopic examination of the intestine, the preparation is the same: three to four days before the prescribed procedure, you should limit the intake of food containing fiber and plant fibers; 12 hours before the examination, only water should be consumed and it is imperative to cleanse the large intestine with an enema and / or with the help of laxatives (oral or in the form of rectal suppositories). 

Technique of the sigmoidoscopy

For the procedure, the patient is placed on the left side, since the localization of the sigmoid colon is the left iliac fossa (fossa iliaca). After palpation of the rectum, a flexible sigmoidoscope is inserted through the anus (maximum depth is about 60 cm).

To expand the lumen of the intestine and provide a clear image on the monitor (transmitted from the endoscope camera), balloon air is injected into the intestine (insufflation).

During the procedure, a tissue sample may be taken for histological examination. [3]

On average, sigmoidoscopy lasts no longer than 20 minutes.

Contraindications to the procedure

Among the main contraindications for sigmoidoscopy, experts note:

• unconsciousness;
• myocardial infarction and post-infarction condition;
• acute or severe cardiopulmonary failure;
• acute and subacute stages of colitis;
• the presence of an anal fissure;
• large abdominal hernia;
• intestinal bleeding;
• bowel perforation or peritonitis, which can clinically present as dark tarry stools (melena) associated with gastrointestinal bleeding;
• patients undergoing outpatient peritoneal dialysis.

Complications after the procedure

The consequences of this procedure are a short watery stool, discharge of gases from the intestines, intestinal cramps (with minor painful sensations). But with the active stage of intestinal inflammation, severe pain is possible. [4]

The procedure for endoscopic examination of the sigmoid (and rectum) colon have complications such as:

• bleeding of varying intensity (especially with a biopsy);
• perforation or rupture of the intestinal wall mucosa.
• severe abdominal pain.

Care after the procedure

Recommendations for the care and rehabilitation after sigmoidoscopy relate to nutrition: a diet is needed with the temporary exclusion of foods that increase the load on the gastrointestinal tract, and fractional food intake (6-7 times a day) in small portions.

Reviews

In addition to the purely emotional reviews about sigmoidoscopy as an unpleasant procedure, most patients note the discomfort that they felt both during the examination and for a short period of time after it. But, as studies have shown, it is with the help of this examination that up to 60-75% of all precancerous or small malignant neoplasms of the large intestine can be detected.