A sigmoidoscopy is a medical procedure that is used to look for the sigmoid colon, which is the lower portion of the colon or large stomach. This part of the colon is next to the anus and rectum.
Following symptoms are diagnosed:
- Belly pain
- Polyps (abnormal growths)
A sigmoidoscopy can also be used to take a sample or a biopsy of tissues. And it may be used to remove polyps (swollen veins in the rectum and anus) or hemorrhoids. This is also a screening procedure for cancer of the colon and of the rectum.
A sigmoidoscopy is performed using a thin, flexible tube known as a sigmoidoscope. The tube comes with a tiny light and a camera. The tube is inserted into the anus and slowly passed through the rectum to the lower portion of colon. The tube will be used to blow air into the colon, which will cause the colon to swell up a little to increase visibility.
Why is sigmoidoscopy required?
A sigmoidoscopy can be used to investigate or treat certain diseases or structures including:
- Ulcers (sores)
- Inflammation (redness and swelling)
- Diverticula (pouches on your colon wall)
- Strictures (narrowing of your lower colon)
It can also be used to investigate the following:
- Changes in your bowel habits
- Lower belly pain
- Itching around your anus
- Blood or mucus in your stool
- Low iron levels
- Low blood counts
A sigmoidoscopy is a screening test used for colon and rectal cancers. After the age of 50, it is recommended that every person should undergo this screening test.
Based on certain clinical conditions, the physician may recommend sigmoidoscopy. If any polyp is seen on this test, then further colonoscopy may be advised.
Preparation for sigmoidoscopy?
The patient will be advised on bowel preparation. Laxative, enema or a rectal laxative suppository will be prescribed. Or a special fluid will be given for bowel preparation. Instructions about diet and fasting will be given.
Inform the physician if:
- the patient is pregnant
- allergic to any medication
- taking any additional medication
- having any comorbid conditions
- bleeding disorders or taking any anticoagulants
If any additional information needs to be shared by the physician will be shared with the patient.
In an ambulatory setting, or as part of hospital stay, sigmoidoscopy can be performed. The manner in which the examination is performed will vary based on the situation and the procedures. A sedative or anesthesia is usually not needed before the examination.
Preparation and Positioning
The patient is asked to lie on his /her left side with knees moved towards the chest.
Procedure of performing sigmoidoscopy
- Initially a rectal examination is conducted to check for blood, mucus or stool and also dilatation of anus is done.
- A quenched tube is inserted into the anus and pushed till the rectum and the colon’s lower part. After checking the lower part of the colon, the tube is retracted.
- Air is inserted into the bowel for better visibility. This may cause some discomfort. Liquid stool is removed by a suction instrument.
- Small instruments are inserted through the sigmoidoscope to take biopsy, or cut a polyp and to stop bleeding. Later the cut specimens are sent for histopathological testing.
After a sigmoidoscopy?
Before getting up from the patient bed, lie down on the back or side for a few minutes and then slowly get up and then stand, this makes the patient feel less dizzy.
The patient is usually allowed normal activities and to take diet, but in some instances it may be different.
In case a biopsy has been taken, a small amount of blood may be seen during bowel movements, which will subside in a day or two.
Patients may pass a lot of gas and experience pain due to gas. Ambulation will help reduce this pain.
Side effects include:
- cramping or discomfort in the lower abdomen
- bleeding from the rectum
In very few instances, there may be a puncture in the colon due to the procedure, which will need corrective surgery.
An abnormal outcome may show:
- inflammatory bowel disease, such as ulcerative colitis
- cancer of the colon or rectum
In case of abnormal outcome, additional procedures or investigations may be recommended.
Risks and limitations
The sigmoidoscopy procedure, when performed by a qualified practitioner, is considered secure and the risk of complication is very small.
When to obtain care
If the patient experiences any of the following, should seek medical advice immediately:
- severe pain in your abdomen
- continued bleeding from your anus