My thoughts:
Cola can cause gas and problems. I drink only water or tea when away from home.
Tips to retain enema contents: Have a BM before inserting.
If that doesn't happen, use an empty enema bottle to have a warm water enema (use previously boiled water). If the result is a BM, at least you haven't wasted a first bottle before retaining the second.
Then stay on left side for 30 minutes,etc.*
If you're worried about
retention during the night, use an old towel or Dollar Store flannel lined table cloth to protect your sheets. I have taken them on vacation to prevent making a mess.
Sanitary liners and pads work, too.
A warm water enema before going out can help in the "clean out" process before going shopping, etc. Might avoid a bathroom trip.
A urologist told me that doing "kegel" exercises helps with both urine and fece retention so practice squeezing your butt cheeks for a count of 5 or 10 and releasing slowly. Builds up related muscles. Sometimes I practice while driving.
*Can also help to retain enemas.
Hope this helps someone