Sudden severe stomach cramps, nausea, hot flashes, vomiting

[dutchgirl22]

Hello, I hope someone can help me here!
Since the beginning of this year I've had these random 'attacks' which always start in the evening around 8~10PM with cramps in my lower stomach, within a few hours they've become so painful that I start to feel nauseous. Usually I go to the toilet, have gas and poop a bit but then I have to wait another 15 minutes until I can go again. Around 2-3AM I vomit, or I force myself to because the cramps only become less painful after vomiting, I also experience hot flashes during these attacks. The first time this happened to me I thought of food poisoning but it happens about once every 3~4 weeks very randomly and not after consuming specific kind of food but the pattern is always the same, it never starts in the morning and the cramps don't go away unless I vomit. Since the beginning of this year I also get diarrea whenever I drink alcohol or eat very spicy food, I also have heartburn most of the time. I have to wait very long after eating until I can do sports because it sometimes upsets my stomach as well. The doctor wasnt very helpful last time I visited so I was wondering if anyone here knows what this could be!  I'm a 22 year old woman living a quite healthy lifestyle, not pregnant.