Chronic cannabis abuse may cause a distinct medical condition characterized mainly by severe recurrent vomiting, doctors from Omaha, Nebraska, report.

In the World Journal of Gastroenterology, Dr. Siva P. Sontineni and colleagues from Creighton University Medical Center describe a 22-year-old man who had been using marijuana for 6 years.

"He suffered severe vomiting episodes with visits to the emergency room requiring expensive investigations and hospitalizations," Sontineni told Reuters Health. "Each episode would occur periodically and there was a peculiar phenomenon of hot showers helping to relieve his symptoms transiently."

When the patient abstained from smoking pot, the vomiting symptoms and abdominal pain resolved.

The precise mechanisms leading to the vomiting syndrome and the questions of why it appears only after several years of marijuana use and why hot showering helps relieve the symptoms are being studied.

"Given the high prevalence of chronic cannabis abuse worldwide and the paucity of reports in the literature, clinicians need to be more attentive to the clinical features of this under-recognized condition," Sontineni and his colleagues advise in their paper.

Since the publication of this case report, Sontineni has had several e-mail messages and phone calls from individuals recounting similar symptoms they have experienced while using marijuana. "It clearly shows that the 'cannabinoid hyperemesis syndrome' is more prevalent than the medical community currently recognizes."

People with the condition "need to receive appropriate counseling that the syndrome is curable with abstinence from abusing the cannabis," Sontineni said. "This can save valuable time and resources for the patients and healthcare systems."

SOURCE: World Journal of Gastroenterology, online March 14, 2009.