Doherty returns to Ireland until end of July
The winger signed a two year contract at Portman Road last summer after impressing while on trial at Town from the Irish club.
He has not featured in the first-team this season though and Town boss Mick McCarthy has given him the green light to return to his former club on loan.
The Irish league season runs from March until October, with the loan taking Jack up to the end of July when the transfer window opens.