Yes I Have Had Pains On My Left Side Just

Yes I have had pains on my left side just below my rib cage for 3 weeks. I suffered from constipation for cople of days than I would go....I use to have bowel movements twice a dy. This past weekend i had a bowel movement that was yellowish mucus and looked like sting of balls.....same day i past mucus stool that looked like string as well....I still have pain left side rib but felt great after passing all that stuff...what could it be? IBS perisites?