The following appeared in the House Calls column of the Hamilton Spectator on January 19, 2011.
Q: My eight-year-old son often experiences severe bouts of vomiting and nausea that can last up to 12 hours. The attacks disappear as quickly as they start. What is causing this and what can be done?
A: These episodes sound like a condition known as cyclic vomiting syndrome (CVS). Many other illnesses start with nausea and vomiting, but CVS is characterized by attacks of vomiting that resolve completely but continue to reoccur in a regular pattern.
It is common for children with CVS to have a family member that suffers from migraines. Similar to migraines, many patients with CVS experience a "prodrome," which signals that a CVS attack is imminent.
Other children may simply wake in the middle of the night and complain they are feeling sick to their stomach.
CVS episodes may also be triggered by stress or exciting events, like birthdays, holidays and family trips. When diagnosing, it is important that the doctor rules out other potential causes before deeming it CVS.
If you recognize the "prodrome," it is useful to start medication at the earliest possible moment. Speak with your child's doctor before administering medication. The doctor may prescribe anti-vomiting or pain-reducing medications.
If vomiting can't be controlled by methods prescribed by your doctor, visit your local emergency department, where medications and a high glucose drip can be given intravenously. A mild sedative may also be administered.
Shutting down the attack quickly is important so patients don't become anxious, which can make matters worse.
Diet has an important role in CVS. As with migraine headaches, it is useful to identify "food triggers". Certain foods such as chocolate or cheese, may set off an attack. These should be avoided.
During CVS attacks, the patients should be given high energy drinks such as juice or pop. However, between attacks, children should be encouraged to have small frequent meals with fewer sweets, fewer processed foods and more high-fibre foods, which are digested slowly.
A late-night meal of oatmeal may be helpful for children who have attacks in the middle of the night.
Over time, attacks will become less severe and less frequent in 80 per cent of CVS patients, although many go on to develop migraine headaches. For those whose conditions don't improve, the physician may recommend daily medication or co-enzyme Q 10 dietary supplements.
The only CVS clinic in Canada is located at the Centre for Child and Youth Digestive Health at McMaster Children's Hospital. For more information on CVS, visit www.cvsaonline.org.
Dr. Robert Issenman is chief of pediatric gastroenterology and nutrition at McMaster Children's Hospital.