I'm sorry you go through this, but no, it's not normal.
You might have endometriosis, along with IBS - I had both. My periods, from the first time I had one, were a lot like yours. I'm a lot older than you, and basically, they just didn't know much, and it was hell.
One thing you could do is ask your mom to take you to a gynecologist. They are much better at dealing with period issues than a hospital is, and since this is something that you deal with every month, you need to find a better treatment plan than just going to the hospital because you're dehydrated.
What worked for me was going on the birth control pill when I turned 18. My mom wouldn't let me go on it before because she thought it would give me permission to have sex. As soon as she saw the improvement I had, though, she regretted that decision.
You may have something else going on, and you need to find out what it is. Maybe the pill is your treatment option, maybe it's something else, but things probably won't get better until you find out.
If you can't talk to your mom (though I'm sure she's aware of what's happening), is there another trusted adult you can talk to? An aunt? A friend's mom? A regular doctor isn't good enough here - you need a specialist, someone who only does women's health stuff.
Again, I'm really sorry you're going through this. I know how much you're suffering, and it sucks. :(
What kind of scans have you had, just ultrasounds? I would see if the doctor can order you an MRI of your abdomen and pelvic region. It's amazing what they can see and how useless an ultrasound is by comparison when trying to figure out what is going on with the muscles and internal structure of the uterus.
Has any doctor ever prescribed Ponstel? (Its generic name is mefenamic acid -- it's a non-steroidal anti-inflammatory like Nuprin and Advil). Women swear by it for period cramping. Even Nuprin and Advil are a lot better for period pain than aspirin or acetaminiphin, because they are anti-prostaglandins and relieve the tendency for the muscles to clench. It can make a huge difference.
Please do see an ob/gyn and see if these things can be tried. If they ignore the connection between IBS and your periods making you sick, don't insist, but do insist on an abdominal MRI. Clearly something is going on and you deserve a diagnosis.
my cousin is the same way, so not sure why people here are telling you it's abnormal. i also have a friend from high school that was and is still this way. she just turned 39 last month. i don't know whether or not this is "normal" but i can at least ease your mind slightly and inform you that you're not alone.
i would, if you're too worried about it, see a medical professional to rule anything out. but i know my cousin and friend have both been to see multiple people over the years and each time have been told it's a side effect of heavy periods.