A colonoscopy is the best method for early detection, diagnosis, and treatment of various gastrointestinal conditions, including colorectal cancer. There are a host of reasons why you may be referred by a GP for a colonoscopy, but ideally, you want to be pre-emptively checking for pre-cancerous polyps or other gastrointestinal anomalies, rather than waiting for symptoms to present, writes dr. Maré du Plessis.
The majority of colonoscopies are performed as part of screening programmes for colon cancer. Most often it is done to investigate the cause of blood in the stool, abdominal pain, diarrhoea, a change in bowel habit, or an abnormality found on colonic X-rays or a computerized axial tomography (CT) scan.
Common reasons for a colonoscopy
The most common reasons for a colonoscopy are:
- Periodic colonoscopies for early detection and preventive measures for people with a family history of non-colonic cancers or specific colonic issues (such as ulcerative colitis or colonic polyps).
- Investigating gastrointestinal symptoms such as blood in the stool, abdominal pain, diarrhoea, or changes in bowel habits.
- A follow-up for previous polyps or colon cancer to monitor for recurrence and detect new abnormalities early.
- Further investigation of abnormalities detected through other imaging techniques and scans, allowing for a more comprehensive assessment.
- For polyps to be removed, and other interventions to be performed to address various gastrointestinal issues, without hospital admittance.
Ideally, everyone over the age of 50 should have a screening colonoscopy. Most patients wait until symptoms develop, but if precancerous polyps are detected during a screening, they can be removed during the procedure, mitigating the potential for cancer to develop.
The procedure
The colonoscopy procedure involves the insertion of a flexible colonoscope through the anus, which is then slowly advanced under visual control into the rectum and throughout the colon. The colonoscope’s camera and light source enable a detailed examination of the colon lining, allowing for the detection, diagnosis, and treatment of abnormalities.
This procedure can be done as an outpatient in a doctor’s room if they have an endoscopy suite with the necessary equipment. There is no reason to fear the procedure.
People understandably imagine discomfort or pain, but you are fully sedated. After the procedure, you can consult and receive immediate feedback on results, and discuss any recommended treatment or further tests.
Also tests for unexplained iron deficiency
Another reason you may be referred for a colonoscopy is when you have an unexplained iron deficiency. Chronic blood loss is usually the cause of iron deficiency, and the most common location of chronic blood loss is in the gastrointestinal tract, so we do a gastroscopy and a colonoscopy to look for an undiagnosed malignancy or lesion in the stomach or colon.
The gastroscopy checks the throat, food pipe (oesophagus) and stomach, which is the upper part of your digestive system. This is often done in conjunction with the colonoscopy which covers the lower part of the digestive system. IB