Or search: voiding, enuresis, excretion, evacuation, elimination, indiscipline, undiscipline, incontinency
2 Syllables: SU
conference
3 Syllables: SUU
complement, confident, Congressman, consequence, consequent, consonance, consonant, continence, continent, dominance, dominant, monument, prominence, prominent
4 Syllables: USUU
incompetence, incompetent, predominance, predominant, preponderant

Found 20 words across 3 groupings. Skipped 4 excess words of a similar stem.