Along with nausea, gastrointestinal distress is one of the symptoms people most consistently describe as the hardest part of acute withdrawal.
Why it happens
Opioids significantly slow gut motility — part of why constipation is a common side effect of ongoing opioid use. Withdrawal removes that slowing effect abruptly, and the gut can overcorrect, producing cramping and diarrhea.
What tends to help
- Loperamide (Imodium) at standard over-the-counter doses, used as directed on the package — this is a legitimate, appropriate use of the medication, distinct from the dangerous megadosing pattern sometimes used to self-treat full withdrawal, which we don’t recommend under any circumstances [link to why megadosing loperamide is dangerous]
- Hydration and electrolytes — this symptom is a major contributor to withdrawal-related dehydration [link to hydration article]
- Bland, low-fiber foods temporarily, if eating at all is manageable
Why this matters beyond comfort
Combined with vomiting, diarrhea is the main driver of dehydration during withdrawal — the closest thing to a genuine medical risk from withdrawal itself in an otherwise healthy adult. Persistent, severe diarrhea alongside vomiting is a reason to seek medical care rather than manage it alone at home.
Medically reviewed by [pending]. Sources: SAMHSA TIP 63.