Yeah, I must confess that foul-smelling gas has definitely been a factor since my DX 6 years ago. And yeah, more intense during flare-ups which is most of the time.
I'm sorry I can't shed more light or offer any advice on the subject ucwarrior, but the general consensus amongst the medical/scientific community and indeed patients, is that in short UC is considered a gassy disease.
As for your putrescine and cadaverine observations, given that an inflamed colon is riddled with mainly undigested rotten decayed organic matter with sloughed-off flesh, it's easy to join the dots when it comes to figuring out that a bad smell will be ensuing.
69m Dx'd may'06 (prob had since'04)
150mg azathioprine-stopped jul28-11
.05mg Lorazapan nightly to help sleep
on and off pred last 5 yrs
started 25mg MTX/folic acid Oct'11-stopped after 3 mo.
started 15mg pred mar4'12
1st infsn. Remicade mar8'12
2000mg vit D daily
800mg calcium daily
Slip. elm daily
Psyllium seed and/or metamucil/benfiber daily