EUO = neuron
EUU…
seppuku
if you think that counts, then
IAA
if not,
EUU
Hmmm, no takers for EUU yet? Anyone mind if I do 2 in a row?
EUU = speculum
IAA…
Well, I see you actually beat me to it, Trunk, but, ewwwwwww!
riata
iae
Pirate!
Arr.
I mean, IAI. 
after committing seppuku, you can use a speculum to look inside the wound.
iai?
finalist
iao
Iai = Impair
Iao?
iao = diamond
iau?
Hiatus.
IEA
dietary
(glad I didn’t get to try dial-up for iau)
iee
sieve
iei
(btw: “Siege” is a better answer for IEE, in that it is both an English word and the name of a Doper, which is bonus points)
IEI - Grieving
IEO - ?
ieo - video
ieu - lieu (DOPER NAME!)
now for IIA
IEO - video
IEU - lieu
(Sorry for the two at once, but I wanted my bonus points for the English word/Doper name thing. :D)
IIA
now that was a creepy simulpost.
minimal
iie
that was creepy.
Yeah, that simulpost gave me the WILLIES…
IIO?
::dons a tinfoil hat::
IIO - libido
IIU
minibus: what I ride to school in.
ioa