Find my polyphthongs! For the purposes of this challenge, a polyphthong is defined as a contiguous slice of a String, that only contains vowels, and has length at least 2. Given a non-empty String as input, your task is to output all the polyphthongs it contains.
For example, &quot;abeoic&quot; has the following contiguous slices (space-separated):
a b e o i c ab be eo oi ic abe beo eoi oic abeo beoi eoic abeoi beoic abeoic

Removing those that contain anything other than vowels, or have length smaller than 2, we get our desired polyphthongs:
eo oi eoi


Your submissions must abide by the following rules:

You can choose either lowercase or uppercase for I/O, but the output case must match the input case.

The vowels are aeiou (for lowercase) and AEIOU (for uppercase). y / Y is not considered a vowel.

The input will only contain printable ASCII.

If a polyphthong appears multiple times, you may choose to output it only once or output all its occurrences.

Any reasonable I/O format and method is allowed (lists of characters are also fine, for both input and output).


Test Cases

Input  ->  Output (lowercase)

r67^^()*6536782!87                -> []
programming puzzles and code golf -> []
aaand... i won!                   -> ['aa', 'aa', 'aaa']
abeoic                            -> ['eo', 'oi', 'eoi']
yah eioo ala                      -> ['ei', 'io', 'oo', 'eio', 'ioo', 'eioo']
@yabeeeayio__e                    -> ['ee', 'ee', 'ea', 'io', 'eee', 'eea', 'eeea']
0ioen0aaiosnjksd                  -> ['io', 'oe', 'aa', 'ai', 'io', 'ioe', 'aai', 'aio', 'aaio']

Note that for test cases 3 and 6, you may output 'aa' and 'ee' respectively only once (See the fourth rule).
This is code-golf, the shortest submission in bytes in every language wins!
Python 2, 102 97 bytes

thanks to @JonathanFrech for -5 bytes



w=input();l=range(len(w)+1)
print{w[a:b]for a in l for b in l if b-a&gt;1&lt;set(w[a:b])&lt;=set('aeiou')}


Try it online!

lowercase I/O