A new study further eases fears that the rotavirus vaccine might increase the risk of blocked bowels in infants -- a concern that led to an earlier version of the vaccine being pulled from the market in the United States. In the report on close to 800,000 doses of the vaccine, which protects against severe diarrhea, vaccinated babies were no more likely to end up in the hospital or emergency room with so-called intussusception -- when one part of the intestine slides inside another like a telescope.