One doctor says the illness is "short and sharp" and normally gone within 36 hours. Photo / Getty Images
Bay of Plenty doctors say a winter gastroenteritis bug is going around and are advising people to have good hand hygiene to stop it from spreading.
Schools are also reporting seeing gastro outbreaks, with one Rotorua principal saying it was "particularly nasty" and he had seen an "obvious increase" insicknesses.
A Taupō man who caught gastro a few weeks ago said it left him "basically bedridden" for an afternoon.
A Rotorua GP said she was seeing "a lot of sick kids" with gastro and the flu, while Toi Te Ora Public Health says viral gastroenteritis is "very infectious" and spreads more easily in the colder months, as people spent more time close together inside.
Gastroenteritis is a general term for diarrhoea and vomiting triggered by an infection and inflammation of the digestive system, the Toi Te Ora Public Health website says.
Out of 125 students at the school, Chapman said about 10 kids were off school each time.
"Then their siblings would soon fall over as well.
"It wasn't a huge number of students, it was just a really obvious increase in the usual thing that we're seeing."
Chapman said some staff members had caught gastro as well, with three or four being off at one time.
Rotorua's Three Lakes Clinic GP Dr Cate Mills said the clinic was also seeing a lot of sick kids and people were coming in dehydrated, vomiting and not able to keep fluids down.
"Some have gastro but a lot have influenza-like infections with diarrhoea and vomiting as well."
Mills said the GP clinics were also "super busy", which made it harder to get an appointment.
Mills put an increase in gastro cases down to the time of year and because last year's flu season was quiet so people were susceptible to getting sick because they did not have immunity, she said.
"So we're having to often rehydrate them and make an assessment about whether they need to be admitted to hospital," Mills said.
Mills said hospital admissions did not happen very often.
She recommended people get checked if they or their children could not keep fluid down or rehydrate themselves.
Mills' advice to those who had gastro was to try to drink small amounts of fluid often and to keep an eye on urine output.
"If they've got less than half their normal intake or less than half their normal output, they do need to be reviewed and checked."
Taupō and Turangi Herald editor David Beck said he and his girlfriend caught gastro a few weeks ago and were "basically bedridden" for an afternoon.
"Our stomachs weren't good for the next three or four days."
As well as vomiting and having diarrhoea, Beck said he felt dizzy and hot.
"At one point I was in bed and I was so hot on my face and my head that I was sweating, but my hands and feet were ice cold."
Beck said he and his girlfriend were taking electrolytes and Berocca "because we were losing so much food and fluid".
"But otherwise [we] just tried to sleep it off."
Beck believed he and his girlfriend caught it from an 80th birthday celebration in Christchurch. His girlfriend's 2-year-old nephew just had gastro.
"Half [of] the people that were there in the next week had it."
Tauranga's Fifth Avenue Medical Centre GP Dr Luke Bradford said the "short and sharp" illness was normally gone within 36 hours. He said it was characterised by a sudden onset of nausea, vomiting and diarrhoea.
"We get little outbreaks sometimes. Unfortunately, it's come at the same time as we've got flu and some Covid still around."
Bradford said people could pick up gastro from traces of the virus left on surfaces.
"If it comes into the house, [practise] good hand hygiene - soap and water. But if you're worried about your child, get them seen [by a doctor]."
He said good hygiene was key to try to stop it from spreading. Someone with gastro should wash their hands after any vomit or diarrhoea and not touch other people's food. Parents of children with it should do the same.
It was important to stay hydrated with Powerade, iceblocks and Pedialyte if necessary, he said.
Bradford said he was seeing the illness more among children than adults.
"I think that's because children look so wretched with it. So I think that people come and get seen for the children whereas grown-ups are able to go, 'oh this sucks and maybe it will pass'."
Toi Te Ora Public Health medical officer of health Dr Jim Miller said viral gastroenteritis was "very infectious" and it was not uncommon to see higher rates during winter.
"The nature of social interaction during winter sees people spending more time in closer proximity indoors, which contributes to gastroenteritis spreading more easily in the colder months.
"If you are unwell, make sure that you drink plenty of fluids, and stay home until at least 48 hours after the last symptoms of diarrhoea or vomiting.
"It is important to seek medical advice if symptoms are severe or persist, especially in the very young or elderly."
What are the symptoms of gastroenteritis?
The infection irritates your stomach and gut, making the muscles tighten and causing vomiting or diarrhoea. You can get sick from an hour to five days after getting infected, depending on the type of bug.
Symptoms include:
diarrhoea
stomach cramps
feeling sick and weak
lethargy
loss of appetite
feeling shivery
headache
fever
Symptoms usually only last a few days, but may last up to a few months depending on the cause.
If your faeces (poo) contain blood or pus, contact your doctor. You should also see your doctor immediately if you:
become very weak
feel drowsy
have sunken eyes
go very pale
stop passing urine
get very dry skin or tongue
How can I care for myself with gastroenteritis?
get plenty of rest
drink small amount of fluids often
avoid tea, coffee, alcohol and dairy products
avoid fatty, oily or sugary food and drinks
take oral rehydration salts if needed - these are available at local pharmacies without prescription.