I'm not really sure if I get the point of your question.
At first: IFS is a variable, that contains a separator, like a tab, a space or something. By default it contains a space, tab and newline.
for-loop loop to a
while-loop, suggested by terdon
while read line
echo $line|cut -d\: -f2
done < /path/to/file.csv
This generates this output:
You can do this with a while-loop as well, in personal I just like the for-loop here more.
What is the loop doing?
At first, the loop reads the first line of the file.csv and saves it to the variable "line".
Inside the loop we echo the variable $line and cut it into peaces. We cut it with the delimiter (-d) ":", because in youre file.csv there is always a ":" between the identifier and the value. with the field-indicator (-f) we only want to show us the field 2 (-f2).
The for-loop ends when the file.csv has no more lines.
For more informations see the man page of cut(1).