Children regularly catch coughs and colds, especially once they start school. Generally, children can come to school if they just have a cough or a cold. General guidance from NHS about common childhood illnesses can be found below but it is important to remember that if your child has a sickness bug or diarrhoea then they must not come to school for 48 hours after the last incident. Further useful information can also be found at the following website:
https://www.nhs.uk/live-well/healthy-body/is-my-child-too-ill-for-school/