Oh! I'm sorry! I didn't read the rest. If you have a spastic colon like that, it might be IBS!
Yes, and sorry if it's obvious, but you have to chew steak and roast beef a whole lot more than hamburger and you can cut them into smaller pieces, both ideas will help digestion. Also, if you eat a steak, you should always have a salad to go with it, helps digestion. With roast beef, it's usually cooked with carrots and potatoes, so salad is not needed, but could be the salt in it that is drying you out a little, so drink plenty of water after a meal of stew.
It's also possible that your digestion is a little sluggish to begin with, and a heavy meal is what's finally pushing it along, so you get that diarrhea and cramps. To keep your digestion in good working order, daily drink extra water, exercise, and eat fiber foods and whole grains.
There's also a chance you are having a problem with digesting proteins and/or fat for some reason, which is way beyond my knowledge, so if my tips don't help you out, then your family doc will need to do a workup on this protein/fat idea, do labs to check various blood counts and glandular numbers, maybe do an ultrasound, whatever he thinks would help him diagnose your symptoms.