Welcome to health care magic.
It could very well be internal hemorrhoids
. You have not noticed external hemorrhoids protruding out of your anal orifice i guess. Anal fissure
also can cause this, but you should have pain over the anus and constipation.
It is better to consult a General Surgeon
than a dermatologist
for your concern. Fiber rich food, fruits, vegetables, Bananas and lot of water will help.
Hope this helped,