My son had rotovirus. It is a very nasty little bug!!! He never vomited,but had very very very bad diareah. It is different for everybody, and some cases are worse. Your little one could have started getting ove rit and picked it up again. It is highly contagious. My son was in diapers when he had it, and my Dr. told me every time I changed his diaper, to tie it up in a plastic bag, take it outside to the trash, and wash my hands RIGHT away. My son is 5 now, and when he was little they had removed the vaccine for it, but it is back out again, and I had my 6 mo. old vaccinated for it. If you get your childs vacs. then maybe you could ask your Dr. about. I tossed the option around for a little while, but in the end my Dr. and I decided that my 6 mo old should get it, b/c my older one is in school, and could easily bring it home. I'm sure if they told you that it was rotovirus, then it prob. is. It is a very had virus to deal w/ and may take a while to get rid of. Just keep your house sanitized, w/ clorox wips, and I sprayed EVERYTHING w/ Lysol, especially the bathroom, and when my son spent most of his time while he was sick!! Hope this helps, and good luck