Balancing columns in InDesign

I have a document that has a section header across the page, then two columns, then another section header across the page, and then two columns after that, etc.  I have had this in multiple text boxes linked together but that is a nuisance when text is added or deleted because all text boxes have to be resized and repositioned.  I would like to have this all in one text box.  I was playing around with various column settings within the text box.  My problem is, if I set the text box at one column and use "Split 2" for the column items, the second column has 5" of blank space at the end of it.  Also, a section with only 5 lines for the columned items does not split into two columns.  I also tried putting the text box at two columns and using "Span All" setting with the same results.  What setting am I missing to get the columns to be of equal height?