Diarrhea and back pain?

Heyyy

I have a small problem… I was in Poland with my sister visiting family for three weeks and everything was cool and everything was fine.

Yesterday, after a long 14-hour drive (we left at 7 p.m.), I noticed I had a bit of a stomach ache, but I thought it was due to stress. We got home around 10 a.m. today. I've had diarrhea for the last three hours. I took medication for it (Stopperan) and it got better, but now it's starting again. And I have a stomach ache and backache, as if I were pregnant.

I don't know if it could have something to do with that, but I had no appetite for four days and barely ate. Then I ate normally again, gained weight, and then lost it again. Could that be the cause? I don't know what to do…

Heat patches are out of the question… I don't have any and they're expensive….

LG K