Yes they do get back in. Exclusion is meant to be a temporary measure. The headteacher has the legal power to exclude a child on disciplinary grounds. It must be explained why the child is being excluded and for how long. Exclusion is a last resort and is a response to a serious breach of school discipline. An excluded child's case can be put to the pupil discipline committee - they can reinstate the child if the exclusion is over five school days and where reinstatement is practical. If the governors uphold a permanent exclusion (expulsion), there is the right to appeal to an independent appeal panel. The Advisory Centre for Education (ACE) provides an information pack about school exclusion and runs an Exclusions Helpline on weekday afternoons.
For further information about the service call the ACE Information Line on 020 7704 9822.
Their website is at
http://www.ace-ed.org.uk/