When i urineate i feel my anus swells. no pain, but seems odd. is this normal?

Needs to be checked: We can not answer your question as we do not have enough information.First of all we don't know your age,and we don't know if you are taking any medicine or suuplement.Also we needs to know exactly what you mean by swelling of your anus.The bladder and rectum/anus share the same nerve supply.There can be feeling of fullness in rectum when you pass urine I will advice you get it checked by your MD

Urination: During the act of urination the anal muscles can press forward sometimes releasing rectal gas. After urinating the anal structures retract. If they don't, a prolapse or rectocele may be present. My sense is you have no abnormality,however.