Examples include heroin, hydrocodone, and hydromorphone. Fully synthetic opioids are not derived from an opiate but still bind the opioid receptor. Examples include fentanyl and methadone [2]. Opioids are often used medically for pain relief but are also used non-medically for their psychoactive and euphoric effects.
A clear liquid diet on the day before your colonoscopy helps clear out your intestines, as well as helping to maintain your hydration.
People may have to change their diet before a colonoscopy, but this depends on what laxative is used. Hospitals may ask people to eat a low residue diet for a few days before the procedure. On the day before the colonoscopy people are instructed to stop eating but drink as much clear fluid as possible.