Mucus and blood in stool, after being told by doctors everything is normal?

For further context, I’ve been doing tons of bloodwork the last few months trying to figure out why I was having blood in my stool, I ended up doing an Ultrasound, a CT scan and a colonoscopy, everything came back normal but the colonoscopy showed 20-25 cm of distal colitis (colitis on the left side) biopsies were taken got the results back on the 19th of December everything was normal, no sign of colitis, crohns, hemorrhoids or anything serious, so I’m really confused. Changed my diet by cutting out sugars and carbs, Still having mucus and blood in stool, what could it be?