Help😭 Bowel troubles

I’ve been getting bad cramps like I need to go to the bathroom, but when I do nothing. Just randomly when I do I’ll just have some diarrhea but the pain comes back a couple hours later and this has been happening for about 3 days, what could this be? I’ve already tested for pregnancy 4 weeks after the act, and it was negative so I do not believe that is the problem. Has anyone had this problem?