What Causes Stomach Cramping, Decreased Appetite And Red Mucus In Stool?

Hi. I had some intestinal inflammation for 2 days: cramping, gas, diarrhea, no appetite and fatigue. I considered it to be the stomach flu. The third day I felt nearly back to normal, though with a decreased appetite. Today is the 4th day & I woke up feeling fine but within an hour started feeling cramps, gassy, and had diarrhea again. Got the chills & went back to bed. Now several hours later, I felt pressure to defecate and all that came out is bright red mucus. Is this an immediate concern? Thank you.