Mornings are a busy time for my stoma too. Like you .I have to empty as soon as I get out of bed. Very often as soon as I have had my first cup of tea I need to empty again,and then once again after breakfast. After this I find it all goes quiet on me for quite a few hours. I wouldnt say mine is straight liquid like you describe but it is usualy thinner than when I empty at other times through the day.
What colour is the liquid earthgirl? Sometimes I do get a yellow frothy liquid first thing in the morning which I presume is to do with stomach acids,its only a very tiny amount when that happens though.
If you are seeing your surgeon on Thursday it cant hurt to ask him about
it. Let me know what he says.