My JW sister in law had something similar. Don't know her exact diagnosis though.
She would have cramping and bloody bowel movements..
She tried all kinds of diet..even herbs a "Sister" recommended nothing worked.
Matter of fact the herbs made her a lot worse.
She ended up having a 'bag" put on and her intestines removed. Lower?
She was a much happier person..no more cramping..etc. She could eat what she wanted and was so happy. They started to travel..something they couldn't do before.Now at least 10 years later she is just fine. She still has the bag but she loves it!..She has a whole new freedom.
My hubby's cousin (not a JW also had the same symptoms..they also put a bag on him. His turned out to only be temporary as he healed up ..I guess because he didn't irritate it with quack cures.He was able to have it removed after a few months.
He hasn't had any problems since!
So follow your Dr's advice as to diet etc. You can't keep going on like that and being miserable!...
Hope you feel better soon..
Snoozy Q