I have a British passport and a standard tourist visa which I received at the airport on arrival. I arrived to Thailand on the 5th of December. I want to travel to Malaysia and Cambodia and then return to Thailand for my outwards flight home from Bangkok - BEFORE the visa expires. I will travel within the dates of my visa - is it okay to fly in and out during this time or should I get a re-entry stamp? I can't make sense of the information online - please help.
* I am in Krabi at the moment. If I need a re-entry stamp - can I do this at the airport rather than the immigration office?