You could try this site, I believe what you are describing is the same thing as CVS but I may be wrong.
Here's some info I copied:
The terms CVS and abdominal migraine often have been used interchangeably because of overlap in clinical criteria. Indeed, the key criteria, except vomiting, in abdominal migraines are identical to those in CVS: recurrent, stereotypical, and severe episodes of abdominal pain; punctuating well periods; autonomic symptoms (eg, pallor, lethargy); and a family history of migraine headaches. As a result, symptoms of abdominal pain and vomiting allow many children to be diagnosed with CVS or abdominal migraine. When both symptoms occur, the authors use the predominant or consistent symptom as the primary label
Here's the link: http://www.cvsaonline.org/