Gastrointestinal symptoms are among the most physically distressing parts of opioid withdrawal, and the ones most likely to lead to dehydration if severe.
Why it happens
Opioids slow gut motility and affect the brain’s vomiting-control center. Withdrawal reverses both effects abruptly, often producing nausea, vomiting, and (separately) diarrhea in the same window.
What tends to help
- Small sips of clear fluids frequently, rather than large amounts at once
- Bland foods (crackers, toast, rice) if anything can be tolerated
- Anti-nausea medications — several over-the-counter and prescription options exist; a doctor can advise which is appropriate given anything else you’re taking
- Electrolyte replacement if vomiting is significant, to prevent dehydration [link to hydration article]
When this becomes a medical concern, not just an uncomfortable symptom
- Inability to keep any fluids down for an extended period
- Signs of dehydration: dizziness, very dark urine, confusion
- Vomiting blood
Any of these warrants medical attention rather than waiting it out. [“when to go to the ER during withdrawal”]
Medically reviewed by [pending]. Sources: SAMHSA TIP 63.