Colonoscopy

The colonoscopy department of Asian Institute of Gastroenterology performs one of the largest numbers of colonoscopies per year in the world (more than 10 thousand colonoscopies per year) by experts in the field.  Colonoscopy is a test which allows the doctor to look directly at the lining of the large intestine (the colon). Diagnostic colonoscopy is recommended for change in bowel habits, occult or frank blood in the stool, unexplained anaemia and as a screening test for colon cancer. In order to do the test, a colonoscope is carefully passed through the anus into the large intestine. The colonoscope is a long flexible tube, about the thickness of your index finger, with a bright light at its tip. The video camera on the colonoscope transmits images of the inside of the colon to a monitor allowing the physician to examine the lining of the colon checking for any disease or abnormalities. If necessary, polyps or other types of abnormal tissue can be removed through the scope during a colonoscopy. Tissue samples (biopsies) can be taken during a colonoscopy as well.

Diagnosis: Colonoscopy can help doctors diagnose the reasons for

• Changes in bowel habits
• Pain in Abdomen
• Bleeding per rectum or evaluation of unexplained bleeding from the gastrointestinal tract
• Unexplained weight loss
• To evaluate abnormalities in the large intestine in other imaging like ultrasound and CT scan
• Unexplained anaemia
• Diarrhoea of unknown cause
• Diagnosis and surveillance of colonic cancer
• Colonoscopy can also detect inflamed tissue, ulcers (like in Inflammatory bowel disease or ulcerative colitis), and abnormal growths.

The procedure is used to look for early signs of colorectal cancer. The doctor can also take samples from abnormal-looking tissues during colonoscopy. The procedure, called a biopsy, allows the doctor to later look at the tissue with a microscope for signs of disease.

• Chromo-endoscopy: A dye is sprayed over colon that will help to diagnose early tumours and helpful in colonic cancer surveillance especially in high-risk groups like patients with inflammatory bowel disease.
• NBI (narrow band imaging): is a modality when applied with colonoscopy can help to differentiate malignant tumours from benign colonic tumours without the need for biopsy or can help to direct biopsies from specific sites so that diagnostic yield is high.

Treatment:

Colonoscopy can help doctors with the following issues

• Removal of polyps (polypectomy)
• Removal of large polyps/ tumours by endoscopic mucosal resection(EMR) or endoscopic submucosal dissection (ESD) which was earlier thought to be only removable by surgery
• Dilate narrowed segments (stricture dilation) of the large intestine and place metallic stents across them (colonic stenting)
• Banding for haemorrhoids (piles banding)
• Control of bleeding from ulcers, vascular malformation, growth or a tumour
• Rectal foreign body removal
• Palliative treatment for obstructing tumour ( metal stenting) or bleeding tumour ( laser, electrocoagulation, heater probe, injection)
• Decompression of megacolon or volvulus

Interventions:

• Polypectomy- polyps are removed by snare
• Endoscopic Band Ligation (EBL) for piles- band applied for the eradication of piles
• CRE (Controlled radial expansion) balloon dilatation for stricture dilatation
• Argon Plasma Coagulation (APC)- bleeding vessels are coagulated
• Endoscopic Mucosal Resection(EMR)- polyps are removed by lifting them up by sub-mucosal injection
• Endoscopic Sub-mucosal Dissection (ESD)- tumours or polyps with deep extension are removed en-bloc or piecemeal with this procedure, surgery can be avoided.
• SEMS (Self Expanding Metal Stent) placement- for obstructing cancerous growth that is not amenable to surgery, SEMS can be placed for symptomatic relief
• Glue injection/ sclerotherapy for bleeding varices- in liver disease patients dilated veins (varices) which are bleeding can be obliterated by this technique

 Preventive:

• Colonic cancer surveillance- colorectal cancer is on the rise in Asian countries. Surveillance is recommended in average and high-risk patients to detect this dreaded disease in the early stage which may help in endoscopic treatment avoiding surgery.
• Surveillance of patients with IBD (Inflammatory Bowel Disease)- Patients with long-standing IBD are prone to develop colorectal cancer which can be screened by colonoscopy combined with chromo-endoscopy or NBI.
• Early detection and characterization of premalignant colonic polyp followed by removal.

Early detection and characterization of premalignant colonic polyp followed by removal