Yes, an episode a few weeks ago is entirely consistent with CVS
A patient with CVS whose last episode was a few weeks ago is still experiencing CVS—this is the expected inter-episodic phase of the disease. CVS is defined by recurrent stereotypical episodes separated by symptom-free intervals, and the Rome IV criteria specify that episodes must be separated by at least 1 week 1.
Understanding CVS Temporal Patterns
The defining feature of CVS is the presence of well periods between episodes, not continuous symptoms. The typical pattern includes 1:
- Episodes lasting <7 days (though 15% of patients have episodes lasting longer than 7 days)
- Inter-episodic intervals of at least 1 week where patients return to baseline health
- At least 3 discrete episodes in the past year, with 2 occurring in the prior 6 months
A few weeks between episodes falls well within the expected pattern for CVS. In fact, episode frequency varies widely—patients with mild CVS may have <4 episodes per year, while those with moderate-severe disease have ≥4 episodes per year 1, 2.
The Four Phases of CVS
CVS progresses through distinct phases, and your patient is currently in the inter-episodic phase 2, 3:
- Inter-episodic phase: Symptom-free period between episodes (where your patient is now)
- Prodromal phase: Warning symptoms like impending doom, anxiety, diaphoresis, lasting median 1 hour 2
- Emetic phase: Uncontrollable vomiting lasting hours to days 2
- Recovery phase: Gradual return to baseline
Critical Distinction: Coalescent CVS
Be alert for a subset of severe CVS patients who lose their well periods over time. Some patients develop "coalescent CVS" characterized by 1:
- Progressively fewer asymptomatic days between episodes
- Eventually daily nausea with intermittent severe vomiting episodes
- This pattern unfolds over years, not weeks
If your patient has clear symptom-free periods between episodes (as suggested by "a few weeks ago"), this is classic CVS, not coalescent disease 1.
What You Should Do Now
During the inter-episodic phase, focus on prophylactic therapy and episode prevention 2, 3:
- Classify disease severity: If she has ≥4 episodes/year lasting >2 days requiring ED visits, she has moderate-severe CVS and needs prophylactic therapy 1, 2
- Initiate amitriptyline 25 mg at bedtime, titrating to 75-150 mg nightly (67-75% response rate) 2, 3
- Educate her to recognize prodromal symptoms (impending doom, anxiety, diaphoresis, mental fog) and take abortive medications immediately 2, 3
- Provide abortive therapy: Sumatriptan 20 mg intranasal spray plus ondansetron 8 mg sublingual at first sign of prodrome 2
Common Pitfall to Avoid
Do not assume the diagnosis has changed just because there's a gap between episodes—this gap is the hallmark of CVS 1. The concern would be if the pattern changes (episodes becoming more frequent, losing well periods entirely, or new symptoms emerging), which would warrant reassessment 1.
Screen for cannabis use >4 times weekly for >1 year, as this suggests cannabinoid hyperemesis syndrome rather than CVS 1, 2, 3.