What Causes Severe Abdominal Pain Along With Diarrhea And Hot Flushes?

In October of 2014, I started having severe abdominal cramping, which led to what started as an episode of diarrhea. I went and laid down, the stomach pains continued. Then my face started feeling really hot.. Then my hands. It felt like needles stabbing me everywhere eventually, along with my whole body turning red. It also felt like a bad sunburn, hurt to touch, especially my hands and arms. I felt the sensation in my whole body. My hands and lips swelled noticibly, as well. I then had an urge to go back to the bathroom. While I was having another bout with diarrhea, my fiancé said that he heard something hit the wall and came to the bathroom to check on me. I had passed out and fell over. He said I was out for about a minute. When I came to, I got back into the toilet, and he said I passed out again. This time having seizure like movements. I finally came to again. My whole body was bright red still with the burning and needle sensation. I was very weak. We went to the ER .. Brain scan, ekg, blood and urine all came back normal. About an hour after the episode the redness went away. The next day I felt hungover then I felt fine. I followed up with my PCP and she did blood work.. It came back normal. She referred me to a GI .. GI did blood work, colonoscopy, and an upper endoscopy. All came back normal, except the upper endoscopy showed mild gastritis, chalked up to my acid reflux. So we just come to the conclusion it was an isolated event, probably triggered by panic. Fast forward a year and 2 months to January 3, 2015. It happens again. Same exact symptoms except this time my hand swelled so much my fingertips were turning purple. This time, though, I recognized the symptoms and called my fiancé in the bathroom with me so I wouldn t fall again. I lost consciousness. During my being unconscious, my fiancé said my body was making heaving/pushing motions and sounds similar to that of trying to push during labor. He said my stomach was significantly heaving in and out as I was making the grunting noises that would accompany. I however do not remember anything while being unconscious. He said I came to after about 30-45 seconds. And luckily I didn t pass out again. My whole body flush and burning/needle sensation subsided about an hour later, and I went to sleep. I woke up today feeling like I have a hangover again. Does anyone know what could be going on? I m at a loss.