I'm willing to accept any challenge that's given to me as long as it fits my field of expertise. What I'm not willing to do is waste your money and time or my time in fact on a solution or treatment plan that isn't achieving the desired result.
As a clinical practitioner your role is to use the knowledge that you have acquired over the years and apply that the individual client and then use your instincts to present the best treatment plan going forward. Yet at the end of the day your best treatment plan is really only an educated guess. Higher education and greater clinical experience improves the success rate yet it is still an educated guess.
Having worked with a client for the past month, I can admit that we have been unable to achieve the desired result. We pulled out all the stops and used every tool in the toolbox which all resulted in minor results. However we did narrow down the issue to only one of two possibilities, possibilities that I felt I don't yet possess a high enough skill to be able to competently say with 100% guarantee that I would be the best person for the task.
So what did we do? We sat had a chat and we agreed that going forward I wasn't going to be the best practitioner to help. I happily handed over details for a trusted colleague whose expertise lay more towards this particular clients issues. It's rare for me to be unable to help a client, although it does happen. What I can happily say is that although I was unable to help this particular client with this issue, I have made a client for life who I may see again at some point.