Diarrhea isn't necessarily a bad thing; it's a natural way for the body to rid itself of undesirable things. But, of course, if it goes on too long it can be very serious due to the fluid loss and non-absorption of vitamins and minerals. How long did the diarrhea go on? How long did you wait after taking the coffea and the ignatia? A 30c should have been an acceptable potency.

I assume you aren't seeing a professional homeopath? The best thing would be for a professional to take your entire case and prescribe based on those symptoms, as best they can be discerned apart from what you think are the nux proving symptoms. I assume you took nux for some problems usually associated with it, which means, you might have originally needed a remedy that is similar to it. If that remedy is given, it would probably resolve the nux issues. From your description I understand why op. was suggested, and it could possibly be the originally correct remedy (do you tend to get sleepy when you cease activity, and sit down in a chair?), but it's very difficult to tell without taking the entire case.

I don't know how severe your proving symptoms are, but from one of your earlier posts it sounded like you only get them every 3 weeks or so. If that's tolerable, I would say again that it might be better to wait it out than to add more remedies to the mix. But if you find them intolerable, you have my blessing to give Op 30c a whirl. Incidentally, for me, a 30c will last about 6 weeks, a 6c for about 4 days in non-acutes. With a 200c I'm looking at 4-6 months, but I am admittedly outrageously sensitive!

Dani