Coed is a term that was born in the nineteen thirties when women enrolled in previously all-male colleges, and it is a term that should have died there. Writers today are careful about not using other sexist terms, but coed is still prevalent. Short for coeducational student, it is demeaning when used as a term for a college woman. It says that men are students, and women merely co-students.
Writers who do not fall into that trap often fall into another, calling a man/woman team, such as police partners, a coed team. Unless it refers to education, it is meaningless. When applied to unisex restrooms, coed might be appropriate, but then, as adults, what can we learn about the opposite sex in a restroom that we don't already know?
So, do your writing a favor, and can the coed.
Intestinal fortitude is another term that ties my guts into knots. I suppose with all the indigestible food that we eat nowadays, intestinal fortitude could refer to the digestion process and the garbage that goes in one end and the crap that comes out the other, but any other application is ridiculous.
So use plain old fortitude or have the guts to say guts, and leave the overly cute and clichéd intestinal fortitude in the toilet where it belongs.
And don't get me started on veggies. I will merely say that kiddies might need to be coaxed to eat veggies, but we are adults, and we should eat vegetables and write vegetables. If you don't find this amusing, we're even. I don't find "veggies" amusing.