Varies. Because of a long half life of 36 hours withdrawal lasts longer than withdrawal from a full opioid agonist like heroin or hydrocodone. Most patients feel the symptoms for 7 to 14 days after stopping the drug. Keep in mind that some withdrawal symptoms can start as you begin tapering off the medication.
If abrupt: days, but. I do a gentle tapering from suboxone over a period of approximately 3.5 months; use the analogy of "landing an airplane": you can go down faster, but expect more turbulence and more stress. When people go to prison and have to stop abruptly, they can, and have symptoms over a period of days. Nobody "wants to feel sick" when detoxing, but detox involves having some discomfort to get back sobriety.