Old man eats fish guts in Italy (4)
I believe the answer is:
pisa
'in italy' is the definition.
(Pisa is a city in Italy)
'old man eats fish guts' is the wordplay.
'old man' becomes 'pa' (both can mean someone's father).
'eats' means one lot of letters goes inside another.
'guts' says to take the centre (the insides of the word).
The middle letters of 'fish' are 'is'.
'pa' going around 'is' is 'PISA'.
(Other definitions for pisa that I've seen before include "Place with leaning tower" , "There's a marked inclination here" , "much-visited city" , "Tuscan city" , "City in Tuscany" .)