Hi I have been on 10mg Sr morphine twice a day for about 4 weeks for knee pain. Went to hospital on Monday and saw a registrar who was very good. He removed some fluid and gave me an injection which seems to be working. He did say he didn't like me being on Morphine so I rang my doctor on Wednesday. He told me to just stop taking it and take tramadol when required. So yesterday I started to feel sick, have got a constant ache in my shoulder and have diarrhoea :'(. Is this normal?