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If you have diabetes
from few years then there are chances that you may suffer erectile dysfunction
due to diabetic neuropathy
but as you have said blocked semen please write clearly whether semen comes out or no.If blocked semen means there is no semen coming out then you will have to consult a Urologist
for examination and treatment.As for the oily substance coming out of your backpassage or rectum it may be due to a fistula which may need to be physically examined.Please consult a surgeon who will examine you and help in solving your problems.