Identify a common side effect of opioid medications.

Opioid medications are well-known for their side effects, one of the most common being constipation. This occurs because opioids bind to specific receptors in the gastrointestinal tract, leading to reduced gastrointestinal motility. As a result, the normal movement of the intestines slows down, making it harder for stool to pass through. This side effect is significant enough that healthcare providers often recommend preventative measures or treatments to manage constipation when prescribing opioids.

Nausea, while it can occur with opioids, is not as universally experienced as constipation. Unlike increased energy or improved appetite—which are not associated with opioid use—constipation is a prevalent and often troubling result of opioid therapy. Hence, the identification of constipation as a common side effect directly relates to the pharmacological action of opioids on the body.