Dear Sir, OCD is a complicated psychiatric illness which requires long term treatment and it is advisable to remain in touch with your Psychiatrist. If you have been taking medications for several years and are absolutely symptom free, then your Psychiatrist may taper the doses and stop the medication. We can then hope that the symptoms do not reappear.

Yes. There are higher chances of relapse, which can be diminished by continuing psychotherapy (CBT/ERP). But the risk of relapse is always there.

It's unpredictable.. that OCD will come or will not come .. sometimes it may not come untill 20 years or sometimes it may return in few months so it is not predictable