Blood after #2 in toilet. no period, no internal pain. can it just be exterior rectal bleeding? should i be worried?

Hello. : Hello. This could be anal bleeding from a condition such as hemorrhoids. However, if this has happened more than once or twice, would recommend that this be evaluated. Even if you have external hemorrhoids, it doesn't mean that is the cause of your bleeding.

Many reasons: Potentially but most common is hemorrhoids, fissures, fistula but less frequently infection or colitis/proctitis, polyps, tumors. No amount of bleeding is normal regardless of the cause. See a colorectal surgeon promptly to identify and treat the cause before more serious problems develop. Not to worry but at least get properly evaluated to be safe.