The average child can expect to get sick around 10 times a year while attending school, according to pharmacists.
The Irish Pharmacy Union (IPU) says that children often suffer three to eight common colds from September to June.
Young students are also likely to suffer from two to three bouts of stomach flu during term-time.
September is normally high season for all sorts of ailments - and, while catching sniffles can be inevitable, doctors and parents' groups say that they can be treated easily.
Bernard Duggan, Honorary Treasurer of the IPU, said that the figures are based on research in Australia, but can also be applied to Ireland.
A community pharmacist based in North Dublin, Mr Duggan said that autumn was a "busy time" for chemists as children become accustomed to both classrooms and cold weather.
However, he stressed that these illnesses were normal and difficult to avoid.
"There are always minor ailments that you don't need to bring your child to the GP for," he said.
"You're not going to be able to completely stop these from occurring, but there are small steps you can take. If you are any way concerned, visit your pharmacist. They will be able to advise you on appropriate treatment or refer you to a GP."
Dr Padraig McGarry, chairman of the Irish Medical Organisation's GP committee, said that it was also a hectic time of year in local GP clinics.
"The norm for a few weeks tends to be a spike in respiratory infections, mainly due to the fact that kids are thrown together in a short space of time," he said.
Dr McGarry added that the number of school bugs could be higher if the preceding summer had been marred with bad weather.
It is the first school year when free GP care for under-sixes has been available, and Dr McGarry said there had been a "slight increase" in younger patients at various practices.
"What has been reported to me is that [practices] have seen an increase in visits to co-op and out-of-hours services," he said.
"That would be in keeping with the trend of parents who are both working," he added. "The IMO will monitor this as time goes on."
He also encouraged families to register their children for the scheme as soon as possible to avoid confusion when illness strikes.
How to treat back-to-school bugs
1. Sore throat/tonsillitis: Paracetamol and lots of fluids. If there are white spots, fever or difficulty swallowing, seek immediate medical attention.
2. Diarrhoea and vomiting: Keep the child at home. Plenty of fluids, even small sips. Check with a pharmacist about rehydration sachets.
3. Colds: Caused by viruses. Treat with paracetamol, plenty of fluids and rest.
4. Flu: A viral infection causing fever, aches and pains. Relax the child and treat with paracetamol if necessary.