My wife joins me in the room while I have my instillments, and she has been wonderful in reminding me to breath (funny how you forget that part when someone is shoving a tube up your penis, and through your tightly clenched sphincter).  This has also helped me discover a couple of tricks to reducing the pain and discomfort.  Though it is hard to relax my legs and buttocks, I have found that breathing deeply helps relax the muscles just a bit.  In fact, taking a deep breath through my nose just as she reaches my sphincter reduces the discomfort substantially.  The second instillment resulted in fewer side effects than the first.  I felt worse on the day of the treatment than I did the day after, but still worked from home that day.