Back is made of many bones disc and nerves.  If he had being operated in 2010 for disc then that doesnt mean he will never get disc problem in future.  It may be had been different level then and also now. In disc surgery only the bulging disc is excised not the whole disc otherwise it causes instability at the operated site.  So it can also be of same level.  Beside what doctor has operated is not the only permanent remedies for ur pain.  Ur brother is having this third episode that means he is not yaking care of his back and is involved in strenuous activities with bad posture.  Effort from him is also expected to stay fit and healthy. Please follow ur orthopaedic consultant advise,  this is a wise advice.

Back surgeries are prone to failures. If it isn't that painful you can try painkillers and rest with physio.