Giving up lactose....how long will it take for things to get back to normal?

[LackaDAISYcal]

I'm giving up lactose in a bid to rid myself of recurrent bouts of diarrhoea (the latest one has lasted almost 10 days and I've had several bouts of it since August.) I'mm not convinced it's lactose, as I've just been dx'd with a connective tissue disease and think It's connected to that, so how long should I give it before going back to my Rheumatologist? I've been gluten free for years, so I know it isn't that.
TIA

Bump....it's been 48 hours now with only a minor improvement in my symptoms. Persevere, or look for other trigger factors?

Anyone?