Background: Cyclic vomiting syndrome (CVS) is a chronic functional GI disorder; a characteristic compulsive "hot-water bathing" pattern is reported to alleviate symptoms during an acute episode. There is limited data on this bathing pattern: proposed mechanisms include core temperature increase via effects on cannabinoid type 1 receptors in the brain, skin transient receptor potential vanilloid 1 receptor stimulation, and blood flow shift from viscera to skin.
Aims: We thus sought to characterize the hot-water bathing pattern in patients with CVS and identify differences between heavy cannabis users in comparison to occasional and non-users.
Methods: We conducted a cross-sectional study of 111 patients with CVS at a single tertiary referral center. Questionnaires regarding clinical characteristics, hot-water bathing, and cannabis use were administered. Patients were classified based on cannabis usage into regular cannabis users (≥ 4 times/week), and occasional + non-users (< 4 times/week and no current use).
Results: A total of 81 (73%) respondents reported the hot-water bathing behavior during an episode. The majority (> 80%) noted a marked improvement in nausea, vomiting, abdominal pain and symptoms associated with panic. Regular cannabis users were more likely to use "very-hot" water (50% vs. 16%, p = 0.01) and time to relief of symptoms was longer (> 10 min) in this group, compared to the rest of the cohort.
Conclusions: Hot-water bathing relieves both GI and symptoms related to panic in most patients which appear to be modulated by chronic cannabis use. These findings can help inform future physiologic studies in CVS pathogenesis.
Keywords: Cannabis; Cyclic vomiting; Endocannabinoids; Hot-water bathing; TRPV1.