Typical first-line agents for the management of ICU constipation include stool softeners (e.g. docusate) and bowel stimulants (e.g. senna glycol or bisacodyl), and these are often used prophylactically in critically ill patients. However, a significant proportion of patients require additional therapy to promote laxation , the most common being osmotic agents such as propylene glycol or lactulose. Often, multiple doses of osmotic agents over several days are required to achieve acceptable laxation rates during critical illness. As such, this has prompted the need for targeted therapy to improve constipation in the ICU.