Bowel preparation is an essential prerequisite for high-quality colonoscopy, while clinical performance and patient acceptability have traditionally guided the choice of preparation, their environmental impact has remained largely overlooked. This study aims to conduct a comparative LCA of 5 current bowel preparations used in clinical practice.

A life cycle assessment was performed independently for 5 of the most current bowel preparation available on the market, with 3 polyethyleneglycols (PEG-4L, PEG-2L-A, and PEG-2L-B) and 2 oral sodium sulfate ones (OSS-1, OSS-2). A cradle to grave boundary method was used from raw extraction to end of life. Main environmental impacts were evaluated including carbon footprint, ecotoxicity, water and fossile resources depletion, human toxicity and eutrophication.

Carbon footprint of the different bowel preparations varied from 0.118 kg CO2eq per unit (OSS-1), 0.585 (OSS-2), 0.684 (PEG-2L-A), 0.685 (PEG-2L-B) and 0.814 kg CO2eq (PEG-4L). Active ingredient had less impact in oral sulfate prep (OSS-1 : 0.08 kg CO2e, OSS-2 : 0.012 KgCO2e) than for PEG (PEG-2L-A 0.6 kg CO2e, PEG-2L-B 0.5 kg CO2eq, PEG-4L 0.8 kg CO2e). Packaging was varying from 0.03 for OSS-1 to 0.454 Kg CO2e for OSS-2. Use of fossile resources varying from 1.6 MJ per unit (OSS-1), 10.7 MJ (OSS-2), 13.9 MJ (PEG-2L-B), 15.6 MJ (PEG-2L-A), to 19.3 MJ (PEG-4L). Biodegradability of the PEG reached 40% at 14 days and 60.4% at 28 days in manometric respirometry test.

Oral sulfate bowel preparation with minimalist packaging (OSS-1) has very low environmental impacts compared to other bowel preparations like PEGs, which active ingredient is consuming far more to be produced, or like other sulfate preparations with very heavy packaging (plastic bottles). Biodegradability of PEG has struggled to meet the established standard at 28 days but not at 14, whereas conventional wastewater treatment plants in our country usually keep sludge for less than 20 days. Environmental sobriety should become a criterion of choice at the time of product prescription and for future ecologic conception of drugs.