I Was In The Hospital From Sunday Night (9/13) To

I was in the hospital from Sunday night (9/13) to yesterday afternoon (9/17) because of an infection related to a now-ureteral stone that led to a fever and vomitting. They put in a stent in on Monday morning and the nurses gave me different antibiotics and fluids through the IV, and gave me morphine injections every 4-8 hours as needed. I was urinating frequently, as expected from the stent and fluids, but I never had any stool.

Since last night, about 9 hours after being discharged, I have had intense stomach pains and diarrhea that is very painful and uncomfortable. Why is this happening and long should I expect it to last?