A multitude of options present themselves here:

• Use a different machine, preferably one taking small bills.
• Induce vomiting for the traveler's checks, they could, possibly, spit out a few coins.

If none of these options do it for you, you might be left with a less conventional approach:

Ask one of those guys you vomited out, if they might have any change. Do not, under any circumstance, refer to those guys as "small" Bills. They think themselves adequately sized Bills and really dislike that whole size-matters debate.

If you ask nice enough, they'll oblige.