Hi I have very similar symptoms to you and I suffer from severe health anxiety. Except mine is more Diarrhea dominant, especially after I eat certain trigger foods. But I alternate back and fourth daily. I went to my GP and they did tons of lab tests. My calprotection was 21 which is normal but my ALP and amylase is slightly elevated instead. All my other lab tests were normal.
I also get very bad GI symptoms when I’m stressed out. Sometimes I go more than 10 times per day when I’m stressed! Try to calm down.
If your stools came back with no blood, then it’s very unlikely to be BC and even chrons or UC. Have you gotten blood tests for inflammatory markers?
Keep an eye on your symptoms, very likely IBS because your symptoms match it and you don’t have “red flag” symptoms.
I have a GI appointment myself in a couple weeks so I will keep you posted to try and alleviate your concerns.
Keep us posted if possible!
Best wishes