Concat two IF statements

I have 4 columns.

Column H is a Manual Entry column

Column I (New Business/Lost clients) and J (organic growth/organic decline) are both IF statements that I have formulated

Column K has a Concat formula which I need to pull a list of both Column I and J into . e.g. if something is in column I but not J then that will make part of the list (vise versa.(if you can think of a better way happy to hear it).

However, if I enter something in the 'Manual entry' column I need that to take the place/overwrite the IF statement columns in column K

Thanks in advance