Only one person out of the 15 admitted to hospital after contracting a virus at the Rhythm and Vines festival will stay there overnight.
Partygoers with severe vomiting and diarrhoea were admitted to an isolation ward at Gisborne Hospital this morning.
Tairawhiti district health board spokesperson Toni Lexmond said 14 patients were sent home this afternoon.
Ms Lexmond said testing was being done to determine what the illness was and what caused it.
Anyone with vomiting and diarrhoea who was at the festival should report it to Healthline.
Earlier, Medical Officer of Health Bruce Duncan said the norovirus-like symptoms were highly contagious.
Dr Duncan said his focus was on preventing a mass-outbreak due to the thousands of people in close proximity at the campground.
About 20,000 people attended the three-day long festival held at Waiohika Estate, near Gisborne.
Meanwhile, police have raised concerns about drug use and drink spiking at the festival.
Tairawhiti's area commander, inspector Sam Aberahama, said the behaviour of the majority of attendees was very good with few arrests or issues during the three days.
"Alcohol use and levels of intoxication of festivalgoers was well managed at the venue," he said.
"However, there were some issues with drug use and an increase in reports of drink spiking."
He said numerous people were treated by St John staff onsite.
Three men were arrested at the festival and charged with possession of ecstasy for supply.
Police stopped 4000 vehicles leaving the campsite this morning and breath-tested drivers.
The results of the checkpoint were good with only a small number over the limit, Mr Aberahama said.
Wanaka police also reported few issues at the Rhythm and Alps festival in the Cardrona Valley.
A police spokesperson said only four people were arrested for minor offences and the large crowd was well-behaved.