I notice the same thing about bananas! I have been eating them quite a bit because they are the only fresh fruit I can have post-surgery and they fill up my pouch like crazy. Probably have to avoid those once I go back to work.
I haven't noticed anything with pizza, though I am gluten intolerant so I make my own and it is pretty benign compared to the sometimes greasy pizza one gets in restaurants. Not to mention that so far I have only been able to put cheese and Canadian bacon on my pizza since I am afraid other toppings might cause my new stoma difficulty. Eventually I will be able to add more toppings:) Then maybe it will go through me more quickly.
I have found the changes in output from eating different foods one of the more perplexing things about my new ileostomy.
-Officially diagnosed with UC in 2006, though had symptoms since 1999.
-Had mild/moderate symptoms continuously until severe flare in autumn 2010 which required 2-week hospital stay
-Took Asacol, Rowasa, Canasa and Prednisone to manage flares but meds stopped working
-Tried 1 infusion of Remicade but had excruciating joint pain and discontinued
-Had permanent ileostomy surgery 11/8/2010