Hello! I had diarrhea for 4 hours and 8am yesterday and my stomach was…

Hello! I had diarrhea for 4 hours and 8am yesterday and my stomach was hurting between those hours. Then since yesterday, every 1.2 seconds there's pain in my stomach like it's pulling or scratching from inside - I don't understand! Has anyone experienced this after giving birth? My gynecologist prescribed dexamethasone at 1.5 ampoules twice a day. Who did the injection, on what week?