Unfortunately, you will not be able to refresh the profile to include changes from the base file. However, you can edit your existing profile to add new fields, or delete fields that are no longer used. For example, if you have modified your import file structure by adding a field for gender, you can edit its IOM profile to add this field by right-clicking on the Field Name field, then selecting the desired option from the pop-up menu.
If you select Insert row before, a new blank row is created. Click inside this row to type in your field name, and map this new field to reflect your import file.
This information can be found in the Import-O-Matic User Guide on page 26. I hope this answers your question. Please feel free to contact our support team with any additional questions at firstname.lastname@example.org or 888-662-8426 x2.