is it treatable?
Yes, through the management of symptoms and dehydration.
Rotavirus
Treatment of acute rotavirus infection is nonspecific and involves management of symptoms and, most importantly, management of dehydration. 
what is rotavirus? It is a genus of double-stranded RNA viruses in the family "Reoviridae". what are some of its symptoms? Nausea, vomiting, watery diarrhoea and low-grade fever.
wiki:1131761
Rotavirus [SEP] Treatment and prognosis
Treatment of acute rotavirus infection is nonspecific and involves management of symptoms and, most importantly, management of dehydration. If untreated, children can die from the resulting severe dehydration. Depending on the severity of diarrhoea, treatment consists of oral rehydration therapy, during which the child is given extra water to drink that contains specific amounts of salt and sugar. In 2004, the World Health Organisation (WHO) and UNICEF recommended the use of low-osmolarity oral rehydration solution and zinc supplementation as a two-pronged treatment of acute diarrhoea. Some infections are serious enough to warrant hospitalisation where fluids are given by intravenous therapy or nasogastric intubation, and the child's electrolytes and blood sugar are monitored.