I’ve been getting IPL treatments in the bikini area and one electrologist stated I needed to wait 6 weeks after an IPL treatment before doing any electrolysis in the same area due to the IPL removing water from the hair follicles.
I’m only doing the electrolysis on the white/gray hairs. Is there any substance to their concern since I believe IPL only impacts tho dark hairs? If there is truth to this, is a full six weeks really necessary or would a shorter time suffice, say 2 or 3 weeks?
First of all, photoepilation (IPL or Laser) has an impact on the skin as a whole. Quite independent on the method, i.e. also after electrolysis, it is really recommendable to give the skin its time to recover. After IPL or laser, it is also useful to give the dead hairs their time to fall out - which, as You should have been informed, takes about two weeks. Otherwise, the electrologist would probably tread hairs which might have already been killed - an unnecessary load on Your skin as well as on Your purse 
Afterwards, of course, sufficient regrowth beyond the initial early anagen stage - ideally we want to see the hairs in the actual steady state in order to work on them with our best possible efficiency (again, good for Your skin and Your purse).
Despite of that i was in a situation where i needed to work on freshly lasered skin and i could do that without problems - but i received an overtreatment and permanent scars just 6 weeks after IPL - so really be careful. But It is necessary to watch the skin reaction even more carefully than in a fully recovered skin.
So: electrolysis is possible short after laser or IPL. But it is better for Your skin to be patient and give it the time to heal it needs. Improves the efficiency and reduces the risk of permanent scars.