What Could Blood Stained Mucus And Bladder Incontinence After Flucloxacillin Intake Indicate?

Hello, I am a 21 year old man. I have recently been to the doctors regarding a skin infection that I had due to ingrown hairs. I was prescribed a week long course of antibiotics, Flucloxacillin (FXN 500). The infection as cleared up, however I am now concerned with some other symptoms I have been displaying. When I have been using the bathroom I have been constipated, however still passing stools. I have now begun to pass mucus with very slight blotchy red patches which I believe to be blood. As well as this after urinating I am relived, but I still have a very slight urge to pass urine again and on occasions I need to use the toilet a second time. I have has a very slight loss of bladder control, passing urine. Can you advise me on what the issue maybe?