Modifier used for more than one method colono

I have been told two separate things regarding what modifier to use when there are more than one method used to remove/biospy polyps for colonoscopies. I was told to use -59 and also told to use -51. My doctor used two separate methods to remove polyps in different locations of the colon so I was going to bill 45383 & 45384 but not sure what modifier to add.

Colon modifier

Modifier 59