I also have same issues as you.
I go back and forth between being constipated for up to 5-6 days, or having loose stools on other days.
Ever since I had emergency surgery for bowel perforation, I’ve had this issue.
Sometimes I eat something and I’m fine,seems next time I eat the same thing,I have to run to toilet and have severe cramping with diarrhea.
Was checked at gastroenterologist for crohns and had testing for malabsorption conditions and all tests were negative.
Now when I’m eating out I worry I’m going to have an accident because by the time I feel the severe cramps,I’ve gone a little
Seems to happen somewhere between 30-45 min after eating.
The doc told me to take Imodium when I’m out just in case.