25 year old male. after anal sex, internal sphincter has trouble relaxing during bowel movements, slowed metabolism, a lot of dribble after urination and pre-cum, soft/unformed feces, white/yellowish/green clumpy discharge on feces sometimes?

If you haven't used adequate protection your risk for STD is high. Get checked in any event. You could visit a men's sexual health clinic. In addition anorectal spasm can be from infection or trauma from anal sex.

many of your symptom seem to be functional. Pl see your MD and get a stool test too. eat a normal healthy diet use sitz baths and hold anal sex till you feel better- which I think you will soon after being seen. Good luck