No answers or relief for infectious colitis

I’ve been suffering with abdominal cramps and diarrhea for over 6 weeks. After 3 weeks I went to the ER where they did a CT scan, and diagnosed infectious colitis. I received IV’s of electrolytes, Flagyl, and Toradol and was given a prescription for 7 days of Cyprofloxacin.
I was told not to take Imodium.
I was feeling better and getting off the BRAT diet when the symptoms returned within a week, and once again the cramps were unrelenting. Another trip to the ER and this time they did a urinalysis, X-rays, bloodwork and took a stool specimen. All tests were negative or normal except for my WBC which is high due to having CLL. I also have a moderate sized hiatal hernia which has caused no problems. I’ve enjoyed a healthy digestive system for most of my 78 yrs.
Anyway, I was discharged with instructions to take probiotics and ibuprofen. So my cramps and diarrhea continue. Again, I was told not to take Imodium.
From the outset, I’ve suspected I have Cryptosporidiosis because the symptoms and course of the infection fit my symptoms, and I believe I got it from contaminated grapes or a chicken-apple salad that tasted “off”. I’ve learned that my stool sample was not tested for Crypto and the test isn’t usually done because crypto is hard to find and requires 3 tests, and will eventually run its course. Imodium (loperamide) is normally prescribed for it. Why am I advised against it, and why wasn’t Pepto -bismol suggested? I’ve been offered nothing except ibuprofen for the pain. I’m trying to stay hydrated and sticking to a bland diet but eating anything triggers the cramping. The diarrhea is reduced to mostly mucous with anal leakage. Fun times!
Would very much appreciate anyone’s input. I’m feeling hopeless.