So Thursday, I got a call from the school. The school nurse said he was doubled over in pain. A few minutes later, I got a call from the doctor's office. The results of his ultrasound were complete. She said he has gallstones. After I told her how much pain he was in, they wanted to admit him.
By the time I picked him up from school, he was still in a lot of pain. I had given him ibuprofen and picked up medication from the pharmacy that is supposed to dissolve gallstones. The pain hadn't subsided at all, so the CF nurse suggested taking him to the ER. Yay, our favorite place, right?
After an entire evening at the ER, and one X-ray later, they found out that he was incredibly constipated. About 30 minutes after they gave him an enema, he was 100% back to normal. So, apparently, keeping the intestines lubricated is extremely important, even though he was having normal BM's.
So, it seems like the gallstones aren't causing any pain, but he will be on the medication to dissolve them for a while, to prevent any complications.
I am very happy that it was a simple fix, and nothing scary like organ damage.