I passed out in the bathroom after heavy cramps. What could it be?

[threeceratops]

I've had an experience that got me fairly scared, so I wanted to write to you and see if anyone can shed any light onto what might be going on. I've had two episodes (one on Saturday early morning, one 6 months ago) of essentially the same thing. I'll describe the one this Saturday, but the previous one was almost exactly the same, with the same pains and the same way it apparently resolved itself.

I was woken up at 3:45am by very strong cramps in my stomach/abdomen. I figured I must have eaten something and decided to go to the bathroom, but was absolutely unable to sit on the toilet for more than 10 seconds because it hurt so much when I was sitting (during this short time there was no bowel movement, and I wasn't "pushing", as it hurt too much). At that point, I decided to get up, but I must have passed out, as I woke up lying on the floor of my bathroom and starting to urinate. I got up, finished urinating in the toilet, and then the insane cramps came back. I realized I couldn't go anywhere, so I lied/reclined in the bathtub. After a while I had a bowel movement (in the bathtub) - it was a relatively large amount, of usual color and consistency. The cramps stopped soon after, although I still felt weak and continued to lie in the tub for 10 or so more minutes, until I felt more bowel movement coming on. I moved to the toilet, and had a pretty large amount of diarrhea. I sat on the toilet for a while (there was no, or at least significantly less, pain, so I could sit normally), and when I felt able, I got up, cleaned up all the mess, took a shower and went back to sleep. I've been fine since (maybe a bit weak, but nothing alarming, and getting better), my appetite is reasonable and my bowel movements are average in all respects. No pains, although my stomach was making some harmless noises later on Saturday, and I was a bit gassy as well.

I would have chalked this down to a very weird reaction to food, but what bothers me is that this exact thing happened 6 months ago. (The only difference being that I didn't pass out then as I was smart enough to slide from the toilet to the bathtub before trying to get up.)

I'm 26, male, white, slim (6'3''/160 or so), with seemingly no relevant medical history, and on no current medications. Until a week ago I was on doxycycline for non-specific, non-Chlamydial urethritis, and on the morning of the previous day I had a local anaesthetic given by my dentist. (Neither of those were present during the first episode last August.)

[Donna3300]

It could be just an odd reaction to something. Sometimes we don't get all the answers. But if it continues go see a gastroenterologist and get checked out.