Background: The use of antiemetic drugs to treat nausea and vomiting during an episode of acute gastroenteritis in children remains controversial. To date, there have been a limited number of clinical trials studying this subject matter and health authorities' recommendations are only based on expert opinion. Surveys have shown that despite this lack of evidence, physicians do quite frequently prescribe these drugs. Dimenhydrinate, a histamine receptor blocker, has been proven safe and effective in controlling post-operative nausea and vomiting in children. To our knowledge, no clinical trial has been conducted to study its efficacy in children with acute gastroenteritis.