Evaluation of gastrointestinal bleeding

• Haemoccult positive stools
• Anorectal bleeding the cause of which is not certain
• Melena after excluding an upper gastrointestinal tract source
• Unexplained iron deficiency anaemia

Surveillance of colon neoplasm or cancer

• Following resection of carcinoma or neoplastic/adenomatous polyp
• In patients at high risk of cancer
• First degree relatives or multiple family members with colon cancer, adenomatous polyps, or polyposis syndromes
• Cancer family syndrome
• Chronic ulcerative colitis with pancolitis greater than 7 years or left sided colitis of greater than 10 years

Inflammatory bowel disease

• Determination of extent of disease
• Confirmation of diagnosis
• Cancer surveillance in chronic ulcerative colitis

For evaluation of

• Clinically significant abnormalities of barium enema/CT
• Clinically significant diarrhoea or unexplained aetiology
• Suspected ischaemic colitis
• Intraoperative localisation of lesion not apparent at Surgery

• Colonic perforation – the risk of perforation of the colon is 0.2-0.4% after diagnostic colonoscopy and 0.3-1.0% with polypectomy
• Immediate or delayed bleeding – Bleeding complicates approximately 1 of every 1000 colonoscopic procedures. Most cases resolve spontaneously. Following polypectomy, bleeding may occur immediately, but, in 30-50% of cases, it is delayed from 2-7 days until the eschar sloughs.
• Transmission of infection – Documented instances of transmission of infection from one patient to another or to endoscopic personnel are extremely rare.
• Abdominal distention – Colonic distention during colonoscopy can cause notable discomfort and may also impair mucosal blood flow. Insufflation of carbon dioxide rather than air during colonoscopy may offer some advantages: carbon dioxide is absorbed from the colon, it is non-explosive, and mucosal blood flow is less affected, thus decreasing the risk of colonic ischemia.
• Postpolypectomy coagulation syndrome – The combination of pain, peritoneal irritation, leukocytosis, and fever after colonoscopy may represent a postpolypectomy burn injury. A conservative approach generally leads to a good outcome.
• Splenic rupture – Although a very uncommon complication, the presumed mechanisms of splenic rupture during colonoscopy include direct trauma to the spleen, marked angulation of the splenic flexure, excessive splenocolic ligament traction, and decrease in the relative mobility between the spleen and the colon.

• Splenic rupture – Although a very uncommon complication, the presumed mechanisms of splenic rupture during colonoscopy include direct trauma to the spleen, marked angulation of the splenic flexure, excessive splenocolic ligament traction, and decrease in the relative mobility between the spleen and the colon.
• Small bowel obstruction – Small bowel obstruction is another rare complication of colonoscopy, although it is perhaps more common in patients who have a history of abdominal surgery and postoperative adhesions.
• Incomplete colonoscopy – An incomplete colonoscopy examination may occur in up to 5-10 percent of cases and may be due to patient discomfort, a colon with many twists, postoperative adhesions, or hernias, poor bowel prep, colonic obstruction, looping, diverticular disease, adverse events and other causes
• Missed lesion during colonoscopy – The most recent multicentre study reported that the miss rate for polyps of all types and sizes was 28%.
• Medication effects – Sedatives used during colonoscopy may cause complications from allergic reactions or, more importantly, from doses that may be excessive for certain individuals and lead to respiratory depression. Serious events may complicate up to 0.5% of procedures. More than 50% of deaths associated with endoscopy are related to cardiopulmonary events.