Hello Pabs72. I choose early evening every night because it suits my schedule of writing and doing other things. However, I would never let irrigation interfere with whatever else I want to do. Thus, If I want to go out for the evening, I would simply defer irigation until I get back - sometimes quite late. If I get in too late, I leave it until the morning.
With most things to do with stomas, I experiment to see what I can and cannot get away with. Some people have said that they can go 2- 3 days between irrigating. I tried and could only manage about 36 hours. This was not suitable for me because the output started mid-day, which somewhat defeated the reason for doing it. However, it is very useful to know that 36 hours is my limit because it doesn't bother me to leave it overnight and irrigate the next morning as and when that becomes necessary. The change in routine doesn't seem to have any adverse effect and that's probably because the timing is not that much different. I just calculate my time according to when I last irrigated so if I irrigate in the morning, I still irrigate in the evening to get back to the routine I prefer.
It will be interesting to hear from people who can go a lot longer between irrigations, to see what they do when tnheir routine is disrupted.
Best wishes
Bill
