Day 4 - major back ache -need advice

Hi everyone,
I've been lurking around enjoying all of the great knowledge on this forum since starting the MC. I am about to end day 4, and I've been starting to feel great mental clarity and calmness after the usually difficult first few days. HOWEVER, on the night of day 2, I began to wake up with lower back pain, and last night (night of day 3) i was up until 4:30 am with this back pain. I took a hot bath in Epsom Salt which gave temporary relief (1/2 hr or so) but not long enough to fall back asleep. My husband rubbed my back, which also gave me temoprary relief, but this morning after my SWF (Salt-Water-Flush) I had extreme lower back pain again. After reading through a thread below, I think I might have kidney stones, since the pain is from that area, and my husand says it feels really stiff back there in the kidney area. So my question is - is this pain from the potential passing of stones? is there anything I can do during the Master-Cleanse to also ease along any kidney stones? I am going for 10 days. By way of background, I am doing the cleanse to try and rid myself of asthma and overall lung congestion that has been getting increasingly worse.
Any advise would be greatly appreciated!