I visited my doctor (about 1.5 months before the end of school) because of this diarrhea, and, while waiting
for my appointment, experienced a very high heart rate. I naturally brought this up to my doctor and he referred me to a pediatrician (for both this and the diarrhea). My pediatrician ran all the tests he could (I am scheduled to see a cardiologist in january and I am scheduled for a renal ultrasound this fall), being the specific professional that he is, which all came back normal.