From WordNet (r) 2.0 (August 2003) [wn]:
flatulency
n : a state of excessive gas in the alimentary canal [syn:
flatulence, gas]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Flatulence \Flat"u*lence\, Flatulency \Flat"u*len*cy\, n. [Cf.
F. flatulence.]
The state or quality of being flatulent.
[1913 Webster]