What is this pain? Is this normal? Is there a way to test it at home? Does it sound serious?

So it's been six days and I still have the runs (going back and forth to the bathroom). I have eaten everything the same as my family, but none of them have it. my stomach is always in a lot of pain, and I just keep going to the toilet. I will wake up in the morning due to the pain of needing to go. And mind you, the pain is really bad. And the pain is so bad it wakes me up. Then when I get up to get ready for school, the moment my stomach hurts, I have to stop what I'm doing because the pain is really bad. when I crouch down, or bend my knees closer to me, the pain starts again. I don't know what's going on. please help. it's affecting my daily activities and affecting me at school. I can't go to the doctor's for another two days. please help
What is this pain? Is this normal? Is there a way to test it at home? Does it sound serious?
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