4 June 2020

We asked Dr Dan Worthley a few questions we commonly receive about colonoscopy. Here is what Dr Dan had to say. 

We often hear from people waiting extraordinarily long times for a colonoscopy, causing distress and frustration. How long will people have to wait for a colonoscopy?  

Waiting times for colonoscopy are a very important issue. Colorectal cancer screening saves lives and saves the economy money, and yet protracted waiting times for colonoscopies fundamentally erode the very premise of early diagnosis and improved outcomes. 

With regard to waiting lists, there are 3 types of colonoscopy:  

  1. Diagnostic colonoscopies for symptomatic patients: person has problematic symptoms, perhaps persistent bloody diarrhoea for instance, and so a colonoscopy could reasonably diagnose and thus direct therapy. Colonoscopy should be performed as soon as possible with the waiting time directed clinically by the severity of the symptoms.  
  1. Diagnostic colonoscopies for asymptomatic patients: such as with a positive poo test from the government screening program, person feels well but we are trying to diagnose cancer and polyps before they develop symptoms. Again as soon as possible, but as a guide colonoscopy should be performed within 120 days. Although it is preferable to make or exclude a diagnosis as soon as possible, it is also a reality that cancers are relatively slow growing and it is unlikely that there would be a medical issue by deferring the diagnosis by 120 days. If you can get a free highquality colonoscopy within 120 days through your local public hospital then that is a good outcome. If you can’t then you should be proactive and evaluate your other public and private options, with the 3 key issues to consider in terms of selecting your colonoscopist being the 3A’s: affordability (how much), ability (how good, ask them about their adenoma detection rate), availability (how long is their waiting time). 
  1. Surveillance/family history screening colonoscopy:less time dependent but given these colonoscopies can be planned years in advance, any competent organisation should be able to accommodate the patient in a timely fashion. 

Has COVID-19 impacted colonoscopy services?  

It’s affected everything hasn’t it? The problem is however, bowel cancers don’t care there is a pandemic going on. They just kept on growing. There was, for a period of time, a government mandated reduction in colonoscopy and other surgical procedures. But now, as we have been able to flatten the curve and ensure access to personal protective equipment (like masks etc), private and public practice are back to usual workloads again. Private practice will fairly easily be able to accommodate and absorb any backlog in cases. It remains to be seen, however, how well the public system will be able to ensure that its waiting lists are acceptable and that our excellent results managing COVID-19 do not compromise the care of patients with colorectal cancer. We need to watch public hospital colonoscopy waiting lists closely and respond if necessary.

Are there risks involved in colonoscopy? 

There are lots of benefits to colonoscopy, finding early cancers and curing advanced polyps before they can turn cancerous. But the 3 most important complications of colonoscopy are:   

  1. Perforation, putting a tear in the bowel wall. This is one of the worst complications but can be fixed. We quote a 1 in 1,000 risk of perforation, although this is dependent on the patient and the proceduralist. 
  1. Bleeding following the procedure, usually this is quoted as a 1 in 100 risk. The bleeding usually settles down and can be fixed if it doesn’t. 
  1. Missed pathology. No test is perfect, and colonoscopy is a highly operator dependent procedure. Nevertheless, colonoscopy is the current best test to diagnose and exclude colorectal cancer and colorectal polyps.

What is the best bowel preparation prior to colonoscopy?

One prep does not fit all. In my practice we use a range of liquid preparations based on patient age, bowel frequency and comorbidities. I think personalisation of bowel preparation is helpful, and can ensure the most palatable, tolerable and, at the end of the day, successful result.