American Board of Orthodontics (ABO) Practice Exam 2026 - Free Orthodontics Practice Questions and Study Guide

Opioids are known to have several side effects, which can vary from patient to patient. Among the common side effects are nausea, vomiting, and constipation. Nausea and vomiting are often associated with the central nervous system effects of opioids, as they can alter the way the body processes signals related to nausea. Constipation is another well-documented side effect due to the opioids' action on the gastrointestinal tract, where they slow motility.

Diarrhea, conversely, is not typically a side effect of opioids. In fact, due to the constipating effects, opioids are often implicated in causing bowel movement irregularities that lean towards constipation rather than diarrhea. This makes diarrhea the outlier among the listed side effects, as opioids are more commonly known to contribute to rather than alleviate gastrointestinal distress related to stool consistency.