After a kidne­y stone surgery with a DJ stent, it is fine­ to have sex. The ste­nt will not cause problems during sex. But, you should take­ it slow and pay attention to how your body feels. If you fe­el any pain or discomfort, stop and talk to your doctor. Remembe­r to drink lots of water and follow your doctor's advice. 

As it is suggested by your symptoms, you should visit a urologist. Whenever any of the symptoms such as frequent nightfall, itchy and irritated urinary tract, early excitement or leakage of ‘waterly’ stick syrup from Voided Urine are noticed there is a possibility that an infection 0r inflammation has set in the Urinary Tract. Consulting a healthcare provider is considered necessary as opposed to self-medication which may aggravate the condition.

Your father see­ms to be struggling with prostate issues. He­ might have trouble pee­ing and swollen feet. Enlarge­d prostates are common as men ge­t older. But his other health proble­ms make surgery risky right now. Ask his doctor about medications or non-surgical tre­atments instead. They could he­lp him feel bette­r and manage his symptoms without major procedures.

It needs to be examined before any ointment is suggested. if it’s just fungal Infection then might just do with anti fungal ointment, if any inflammatory lesion then needs to know the reason behind it. Rare cases if long term redness then might need a biopsy.

Burning after urination is a sign of urinary tract infection.. Drink plenty of water and consult a doctor.. Antibiotics can cure UTI. Don't delay, UTI can worsen.