I Am A 56 Y/o Female, 5', 164 Lbs. With

I am a 56 y/o female, 5', 164 lbs. with history of IBS which causes varying degrees of diarrhea. Also have mild hypertension and take 10 mg of lisinoprol, which keeps my bp around 115/77. Recently have had 3 episodes where I had diarrhea accompanied by tingling in my mouth, redness in my face, and a very rapid heartbeat; bp was up to 177/96, heart rate was at 123 during the episode. Within 10 minutes, my symptoms have diminished significantly, and my bp has gone down to 121/77, heart rate at 96. I'm trying to figure out if this is a cardiac problem or a g.i. problem. Any thoughts?