When I first flared I could only do aroun 2-3 hours. On this flare I can hold them in all night. (This also depends on the severity of the flare.)
This may gross some out, but I found the best way to do it is go on all fours, stick your but in the air. Then my awesome husband helps me out with the actual enema. Then I keep my but in the air for at least 5 mins. Then I lie on my left side for at least 5 and then fall asleep on my right.
Hope this helps,
Mel