What are the causes and management options for my alternating loose and constipated bowel movements since quitting cannabis (marijuana) use two months ago?

Cannabis Withdrawal Syndrome with Gastrointestinal Symptoms

Your alternating loose and constipated bowel movements are most likely due to cannabis withdrawal syndrome, which typically resolves within 1-2 weeks but can persist for up to 14 days after cessation. 1

Understanding Your Symptoms

Your bowel pattern changes are a recognized manifestation of cannabis withdrawal syndrome (CWS), which affects approximately 47% of regular cannabis users after stopping. 1 The gastrointestinal symptoms you're experiencing—alternating between loose stools and constipation—occur because:

• Cannabis directly affects gut motility through CB1 receptors in your enteric nervous system, which normally slow down intestinal transit. 2
• Withdrawal disrupts this system, causing erratic bowel function as your gut readjusts to functioning without cannabinoids. 1
• Symptoms typically peak between days 2-6 after stopping cannabis, with the acute withdrawal phase lasting 1-2 weeks, though you're now at 2 months post-cessation. 1

Critical Diagnostic Consideration

You need to differentiate between cannabis withdrawal syndrome and cannabinoid hyperemesis syndrome (CHS), as they present oppositely but both can cause GI symptoms:

• CWS causes symptoms AFTER stopping cannabis (your situation), while CHS causes vomiting DURING active use. 1
• CHS requires 6+ months of abstinence for complete resolution, so if symptoms persist beyond 2 months, CHS may still be resolving. 1, 3
• Hot water bathing behavior (compulsive use of hot showers for relief) occurs in 44-71% of CHS cases and can help distinguish the conditions. 1, 3

Immediate Management Approach

For your current bowel symptoms:

• Use loperamide (standard antidiarrheal) for loose stools as recommended by the American College of Gastroenterology. 1
• Avoid opioids entirely—they worsen nausea, carry addiction risk, and don't address the underlying problem. 1
• Consider ondansetron if you have accompanying nausea, though efficacy may be limited. 1

Expected Timeline and Monitoring

Since you're at 2 months post-cessation:

• Most acute withdrawal symptoms should have resolved by now (typically within 14 days). 1
• If symptoms persist beyond this timeframe, you may be experiencing prolonged CHS resolution, which requires at least 6 months of continuous abstinence for complete symptom resolution. 1, 4
• Cannabis craving can persist for months or years, but physical GI symptoms should be improving. 1

When to Seek Further Evaluation

Rule out other serious conditions if:

• Symptoms worsen or don't improve over the next few weeks 3
• You develop severe abdominal pain, visible blood in stool, or unintentional weight loss 3
• You experience fever, signs of bowel obstruction, or severe dehydration 3

Additional Supportive Measures

Address concurrent mental health symptoms:

• Anxiety and depression commonly emerge or intensify during cannabis withdrawal and may contribute to your GI symptoms through the gut-brain axis. 1
• Consider psychological support or counseling, as anxiety is a prominent feature of withdrawal. 1
• Assess for other substance use, particularly tobacco, which is highly prevalent (24.5%) in patients with cannabis-related GI issues. 5

Long-Term Considerations

If symptoms persist beyond 3 months:

• Consider tricyclic antidepressants (amitriptyline 25 mg at bedtime, titrating to 75-100 mg) as the mainstay of preventive therapy if this represents prolonged CHS. 1, 4
• Referral to gastroenterology may be warranted to exclude other functional GI disorders like IBS, which can overlap with cannabis-related dysmotility. 6, 5
• Complete abstinence is essential—any return to cannabis use will perpetuate or restart the cycle. 1, 4