Piles or hemorrhoids
Piles are group of inflamed tissues in the anal canal. They may be internal or external. Internal are the most common type. A person with piles may experience a hard lump around the anus, feeling of full bowels after passing stool, blood after bowel movement, itchy anus, red and sore etc. Piles is classified into 4 categories. This is caused due to chronic constipation, chronic diarrhea, pregnancy, straining when passing stool etc.
Fistula can be caused by a number of reasons such as cancer, tuberculosis, trauma, sexually transmitted diseases etc. The symptoms include recurrent anal abscesses, pain and swelling around anus, bloody, foul smelling pus, fever, chills etc.