Suggest Treatment For Stomach Ache, Diarrhea And Rotten Smelling Belches

Was wondering, have a 7yr old male. Burping up roten egg n server belly pain n diarrhea.. this has been goingbon for 4 days.. I AM AN EMT. PALPED OUT HIS BELLY NO TENDERNESS OR GAURDING.. HIS STOOL IS VERY DARK THE FIRST 3 DAYS N NOW BECOMING ALMOST NORMAL BOWL MOVEMENTS ON 4th DAY. SULFURIC ACID, WAS MY GUESS.. BUT FOR 4 DAYS??? SHOULD I GO TO ER.. HE WAKES UP FROM THESE PAINS FROM A GOOD SLEEP. HELP CONCERNED MOMMA. EMT