Does Cannabinoid Hyperemesis Syndrome (CHS) impact bowel movements in a patient with a history of CHS?

Does CHS Impact Bowel Movements?

Cannabinoid Hyperemesis Syndrome (CHS) does not cause diarrhea or altered bowel movements as part of its core clinical presentation. CHS is characterized exclusively by stereotypical episodic vomiting, nausea, and abdominal pain—with no mention of diarrhea or bowel movement changes in the diagnostic criteria 1, 2.

Core Clinical Features of CHS

The cardinal symptoms of CHS are limited to upper gastrointestinal manifestations:

• Stereotypical episodic vomiting occurring ≥3 times annually 3, 2
• Nausea and abdominal pain during acute episodes 2, 4
• Pathognomonic hot water bathing behavior (compulsive use of hot showers/baths for symptom relief) present in 44-71% of cases 1, 3

Diarrhea is explicitly not a feature of CHS 2.

Why CHS Doesn't Affect Bowel Movements

The pathophysiology explains the absence of bowel symptoms:

• CB1 receptor dysregulation occurs in the dorsal vagal complex, which controls emesis, not intestinal motility patterns that would produce diarrhea 2
• Peripheral CB1 receptor activation affects gastric motility and emptying, not colonic transit acceleration 2
• Cannabinoids can inhibit colonic tone and phasic pressure activity, but this does not translate to the clinical syndrome of CHS 5

Critical Differential: Cannabis Withdrawal Syndrome

If your patient with CHS history presents with diarrhea, consider Cannabis Withdrawal Syndrome (CWS) instead:

• CWS occurs in approximately 47% of regular cannabis users after cessation and includes gastrointestinal symptoms such as diarrhea 1, 2
• Timing is key: CWS symptoms (including diarrhea) occur after stopping cannabis, while CHS vomiting occurs during active chronic use 1
• CWS symptoms include irritability, anxiety, insomnia, decreased appetite, restlessness, and gastrointestinal distress including diarrhea 1
• Symptom onset: CWS typically begins within 24-72 hours of cessation, peaks between days 2-6, and resolves within 1-2 weeks 1

Management of Diarrhea in Cannabis Users

If diarrhea is present in a patient with cannabis use history:

• Use standard antidiarrheal agents such as loperamide for diarrhea in Cannabis Withdrawal Syndrome 1, 2
• Avoid opioids entirely, as they worsen nausea, carry addiction risk, and do not address underlying pathophysiology 1, 3
• Assess for concurrent mental health disorders (anxiety, depression) which are common comorbidities 1
• Provide cannabis cessation counseling and psychological support given anxiety is a prominent feature of withdrawal 1

Common Pitfall to Avoid

Do not attribute diarrhea to CHS. If a patient with known CHS presents with both vomiting and diarrhea, you must distinguish between:

1. Active CHS episode (vomiting during ongoing cannabis use) + separate gastrointestinal pathology causing diarrhea
2. Cannabis Withdrawal Syndrome (if they recently stopped cannabis) causing both symptoms
3. Another diagnosis entirely that requires appropriate workup 2

The presence of diarrhea should prompt you to broaden your differential diagnosis beyond CHS 2.