28 yo male, very tiny specks of blood on tp during last wipe. some itching, and chafing, no anemia, negative occult test. what are the possible causes?

External hemorrhoid: What you described suggests external hemorrhoids. You may try over the counter remedy. If that does not help in 2-3 weeks, you may wish to consult a doctor. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.

Abrasion: Mild local abrasion. From now on, use some skin lotion [Aveeno, Eucerin, etc] on the paper for final 2 wipes.