Respected Sir/Madam,
My name is _______ (name) and I would state that my student ID number _________ (mention student ID number).
Courteously, I would like to inform you that I am studying in your reputed college’s _________ (department) and I will not be able to attend college on __/__/____ (date) as I am suffering from stomach ache.
It is to request you to kindly grant leave for the said date. I shall be highly obliged for your kind support.
Thanking you,
_________ (Your name),
_________ (Roll number),
_________ (Contact details)