I have multiple (n) bed files with identical intervals and one unique information column. I would like to combine these into one bed file with n information columns.

file1.bed:

chr    start     stop     col.foo
chr1   1         10       foo
chr1   20        30       foo

file2.bed:

chr    start     stop     col.bar
chr1   1         10       bar
chr1   20        30       bar

desired_output.bed:

chr    start     stop     col.foo    col.bar
chr1   1         10       foo        bar
chr1   20        30       foo        bar

I tried using bedtools merge, but don't see an obvious solution. This only keeps the information column of one of the files:

bedtools merge -c 4 -o collapse -delim = "\t" -i file1.bed -i file2.bed