The IUI Procedure (Intrauterine Insemination) only takes a few minutes and involves an an instrument called a speculum to be inserted into the woman’s vagina, enabling the walls of the vagina to remain open, just like a smear test. A catheter which is a thin, flexible tube is then placed inside the vagina and guided into the womb. There may be a little discomfort felt during the IUI procedure, however the process is usualy painless. The sperm sample will then be passed through the catheter and into the womb.
Further reading on the IUI Procedure
IUI (Artificial Insemination) - Wikipedia
IUI – How It’s Performed – National Health Service (NHS)