Sometimes I feel like everthing changes several time during the day.
Like you, it has been 9 months now. I may have a great deal of output for hours or days then nothing for days. The opening size of my appliance seems too tight at times and too lose at other times. I haven't developed any consistancy. I use a two piece apliance and the base last about 5 days. Changing the outer bag allows me to check things at least once a day. Early on, I changed the base more often to be sure the skin was okay. Now, I wait several days unless there is burning or itching or it seems to be coming lose.
One thing that changed with my surgery is that I don't like eating. I am 67 and fat but I don't want to lose any more weight (lost 40 lbs with surgery). As I lose weight, skin sags lower and lower. Fat is better for me. So much of my eating now is for maintainence and consistancy.
It seems that for me variability is the norm. As long as I have no pain, no health problems, no difficulties ... I just accept the changes. My decision is ... when/if there is pain, increased redness or soreness, or anything dramatic I will see my doctor. For most of my issues, I have found my answers here online. I don't have a lot of local resources but have learned amazing things from the amazing people on this site. Most everything I have experienced is better in a day or two.
Many people have conditions that cause lots of problems and issues and additional surgeries. I think they each have learned when to seek outside help. It is a very individual thing. My advice for myself is to trust my gut (pun and not)). If it feels wrong, painful, or dangerous - check it out. If it is something that feels like it can be put on hold for a day or two with no difficulties, wait it out.
The hardest thing for me was not knowing how things were suppose to be. I didn't even know about showering. With fingers crossed, I say it has become easy.
I don't know if this helps any but it is what I have learned.
Carol