A comprehensive review finds that the MMR vaccine, which protects against mumps, measles and rubella or German measles, does not cause serious childhood illness like autism or inflammatory bowel disease.

That's the conclusion of a review of 31 studies involving more than 12 million children published online by the Cochrane Library.

The analysis looked at a variety of studies, including many double-blind studies in which children got fake injections or no injections at all.

Overall, the authors found that vaccinated children had fewer upper respiratory infections but more irritability, fever and joint aches right after vaccination.

The study found no association between MMR and autism or other bowel disorders that a lot of parents worry about.

This study supports the well-established position of all the major pediatric medical societies that autism starts in the womb and has no relationship to any of the childhood vaccinations.