What does this sound like to you?

3 years old. Stomach pain, frequent diarrhea (therefore bad diaper rash), occasional fever. All this has been since last Thursday. Some blood was in his stool this morning. He'll randomly say like his foot, arm, hand, and/or head hurts. Still got a very good appetite, no vomiting. Is very happy in between stomach aches.

I've been up with him 1-5am because he was constantly shouting his stomach was hurting and pooped 4 times.

Edit

I wanted to see what you all might think before the dr appt. Some kind of stomach flu that's going around