Hi, I Am 66 Yr Old Female Who Normally Had

Hi, I am 66 yr old female who normally had regular bowel movement and for this week after I have had knee surgery, I am having difficulty to use the bathroom. Few days ago is came out in small balls and now today I need to go but again in small pieces but the largest piece is not moving, just stuck in my anus. Please tell me if there is something I can do help relieve it?