Amoxicillin

I have recently been diagnosed with UC and I’m currently on a 6 week course of prednisone which has worked incredibly well. However I’m on my last 2 weeks of prednisone and I managed to get both ears infected and my throat infected. Got prescribed amoxicillin for 5 days and day 1 I have awful diarrhoea with blood in the stools. Should I expect this? Will it carry on after I finish the antibiotics?