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 A colonoscopy is a quick and painless procedure, usually around 30 minutes long, that allows for the full examination of the entire inner lining of a patient’s bowel (colon and rectum).

During the procedure, a gastroenterologist uses an instrument called the colonoscope to perform a colonoscopy.

It is a long, thin, flexible (the scope bends) fiberoptic camera that allows the specialist to visualize the entire colon.

With this thin instrument, the gastroenterologist spends most of the time looking for changes to the normal landscape of your bowel lining and removes anything that looks suspicious.


The Purpose of a Colonoscopy 

Colonoscopy (or colonoscopy of the colon), is the most important colon screening procedure available.

It is done to detect diseases, and to remove polyps that may be indicative of cancer, and the polyps that are no longer active (that is, the polyps that are no longer going to grow into cancer) at that time. 

A colonoscopy may be useful for detecting certain diseases that occur on the outer layer of the colon such as colon cancer, but more often, the colonoscopy is performed to remove non-cancerous growths in the colon.

These polyps are caused by various human germs that do not affect your health but can cause symptoms. 

A person does not need to have any symptoms to have the colonoscopy and you may perform the colonoscopy as an outpatient procedure.

colonoscopy explained - Getting To Know About a Colonoscopy, Or the Endoscopy of The Colon

What To Expect from A Colonoscopy

Like many common procedures, a colonoscopy is an easy one to put off or be scared of.
When preparing for a colonoscopy, it’s important to consume plenty of fluids and follow the diet recommendations of your doctor.

A liquid will be prescribed for bowel preparation that is similar to your stomach wash or laxative.

Being sedated while having your colonoscopy can cause you to develop side effects like a dry mouth, sedation, headache, fatigue and vomiting.

If you are sedated, you might have a difficult time telling you doctor about any pain you may be experiencing. The procedure is supposed to take about an hour, depending on the extent of the find, or another 30 minutes if it’s a small find.

The doctor may then need to send the images and your medical history to your doctor and get his or her opinion on the colonoscopy.  

why you should get a colonoscopy - Getting To Know About a Colonoscopy, Or the Endoscopy of The Colon

Who Should Get a Colonoscopy?

As you may already know, people over 50 are strongly advised to have a colonoscopy every 10 years.

Although most people usually get colonoscopies done under general anesthesia, there are some other options for procedures that may improve your colonoscopy experience.

For example, if you are not comfortable with having general anesthesia or having to lay completely still for a long time, some people prefer the Capsule Endoscopy.

However, most people aren’t aware that even younger adults may have some abnormalities in their colon, because many other conditions can cause changes in the colon lining, such as:

Ulcerative colitis
Ulcerative colitis is an inflammatory bowel disease that causes inflammation on the inner wall or lining of the colon and rectum.

Crohn’s disease
Crohn’s Disease or Crohn syndrome, is a type of inflammatory bowel disease marked by patchy areas in various sections of your gastrointestinal tract that cause ulcerations and pain.

Crohn’s disease can occur anywhere along this pathway, but it most commonly manifests itself as inflammation of the small intestines (ileum) and can lead to impaired digestion, unintended weight loss and serious complications like blockage of the intestinal tract (strictures) or fistulas.

Recurring rectal bleeding
Rectal bleeding has many causes and can occur as the result of a weaker or abnormal area along your digestive tract.
Haemorrhoids are the most common cause of rectal bleeding.
While these and other causes of rectal bleeding may be minor inconveniences, rectal bleeding can be a real concern if you’re losing a lot of blood.

Rectal cancer
Rectal cancer is a type of cancer that occurs on the lining of the rectum. This form of cancer is called adenocarcinoma which means it develops in gland cells. These cancers are not specific to this region but can be found multiple regions of the tract if they spread.

capsule endoscopy - Getting To Know About a Colonoscopy, Or the Endoscopy of The Colon

When Should You Get a Colonoscopy?

It is recommended to start colonoscopy screening for adults over 50 years old, and especially those who have been told that they have polyps or other changes in the way their bowel is lined.

As this is the stage when your chances of developing colorectal cancer are highest, it is always a good idea to schedule a colonoscopy for your screening at this age.

In most cases, the most rapid way to identify colon cancer in a young patient is to perform a colonoscopy. The sooner we diagnose it and remove it, the better your chance of living a normal and disease-free life.

The success rate of colonoscopy screening of the colon is 98 percent. But let’s talk about colon polyps. What is a polyp? 

Polyps Explained

The most common symptom of colon polyps in the large intestine is bleeding in the stools.
The definition of a polyp is any abnormal growth of tissue that projects into a lumen. 

A colon polyp is essentially an overgrowth of tissue in the large intestine. Colon polyps are commonly caused by irritable bowel syndrome or inflammatory bowel disease. 

If you suspect you have a colon polyp, it’s best to see your doctor immediately.

However, even if there are no symptom with visible signs, your doctor can still notice the condition during routine examinations.

cancerous polyps - Getting To Know About a Colonoscopy, Or the Endoscopy of The Colon

Cancerous Polyps Explained

 When a patient has cancerous polyps, the doctor will extract them from the body during a procedure.

They may be called polyps or adenomas where you have lined up multiple protrusions from the colon wall.

The doctor takes a biopsy of the tissues to confirm a diagnosis which leaves a hole where they were removed and can heal quickly by itself.

This usually happens when you have had the same polyp removals over time and these holes don’t heal as easily as before, then it is likely that there might be cancerous cells present which means it’s time for another procedure to remove them entirely instead of just removing the tumors again.

When to Seek Medical Care for Colonoscopy Complications


Call your gastroenterologist for advice if any unexpected symptoms occur, including:

  • Persistent nausea
  • Persistent but minor bleeding
  • Ongoing bloating and abdominal discomfort

We recommend going directly to the emergency room if the patient experiences any of the following: 

  • Severe abdominal pain
  • Heavy bleeding from the anus (rectum)
  • Vomiting

Dr. Schneider is here to provide you with expert medical advice in the field of gastroenterology.

Book an appointment online or contact us  on 011 482-3010 to find out more.


The information on this website is to provide general guidance. In no way does any of the information provided reflect definitive medical advice and self-diagnoses should not be made based on information obtained online. It is important to consult a Gastroenterologist or medical doctor regarding ANY and ALL symptoms or signs including, but not limited to: abdominal pain, haemorrhoids or anal / rectal bleeding as it may a sign of a serious illness or condition. A thorough consultation and examination should ALWAYS be performed for an accurate diagnosis and treatment plan. Be sure to call a physician or call our office today and schedule a consultation.

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© Dr. H Schneider, Registered Gastroenterologist, GI Doc Johannesburg

Our website information is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. Please consult a doctor about your specific condition. Only a trained physician can determine an accurate diagnosis and proper treatment.