The excitement of getting ready for the start of any competition seems to get a lot of people headed to the facilities. Check any bathroom before any type of endurance or high energy race.... It will be pretty busy. Must be the stress and that "fight or flight" response.

Perhaps a prudent approach would be to express any bulk several days prior to an event using a natural laxative (not a stimulant), and then proceed to steadily reduce the bulk in your diet up to, and during, the event.

A protien only diet for any sustained period of time will reek havoc on your microbial flora in your gut, leading to poor nutrient absorption, gas, bloating, cramps, water sequestering, inflammation and other undesirable effects.

If you can get yourself "regular", as in having movements within a specified time period each day (or every other day), it will work far better than any freak dietary change (which usually shocks the system and causes irregularity). At least you'll be better able to predict future "events".

I'm not a doctor.