Commentary: low-volume bowel preparation for colonoscopy – authors' reply


We read the interesting commentary, suggesting the adoption of a split regimen for low-volume poly-ethylene glycol (PEG) preparations, to improve the tolerability and the efficacy of colorectal cleansing.[1]

Similar to high-volume PEG regimens, the adoption of a split regimen for low-volume preparations may become a nuisance for the patients, when outpatient colonoscopies are scheduled in the early morning (i.e. 08:00–09:00 hours).[2] As suggested by the author, patients need to consume the second dose very early in the morning, to match with the 2-h fasting role recommended by the American Society of Anaesthesiology. This would indicate that patients should wake up as early as 04:00 hour, when assuming a 1-h travel from home to the endoscopic centre, and the time needed to take the second dose.

Although it could be argued that colonoscopy is to be infrequently repeated in a life-time, so that the nuisance for an individual patient would be limited, it is also true that colonoscopy is performed each year on several million people worldwide, so that the cumulative loss of quality of life may become relevant. Moreover, a fastidious preparation regimen could, in the long-term, affect the acceptability of colonoscopy as a diagnostic or surveillance procedure, indirectly increasing the incidence and mortality from colorectal cancer. Alternatively, competitive tests such as noncathartic CT colonography or faecal tests – which do not require bowel preparation – could be favoured by the adoption of a troublesome preparation regimen.

A possible compromise between the need of a split regimen for early morning colonoscopies and the acceptability of colonoscopy would appear to be as simple as to shift all the early morning colonoscopies to late morning or afternoon slots. In other words, colonoscopy should be considered an examination not suitable for the early morning timing, when recommending a systematic adoption of a split regimen. This would mean a more profound re-organisation of endoscopic and outpatient clinics with the possible performance of all the noncolonoscopy procedures, such as upper/biliary endoscopies, in the early morning. However, colonoscopists should be protected by a limit to demanding activity before initiating a colonoscopy list, as this could compromise the detection of neoplastic lesions.

Although it could be argued that to ‘re-think’ all the activities of an endoscopy department simply to improve the preparation regimen for (early) morning colonoscopies may be excessive, this should necessarily be done, when considering that no other option is actually available and the prominent role of colonoscopy in the context of population-based colorectal cancer screening.


The authors' declarations of personal and financial interests are unchanged from those in the original article.2