It sounds like Pruritus Ani (intense anal itching). After seeing two doctors and trying different products/diets, I can tell you the the medical community isn't very knowledgeable about it. However, a group to people that have suffered with the chronic anal itching for years have done research and created about problem to treat it. It's called Pranicure and it's an ointment only available online. Look it up and order it as it's for sure the most effective remedy out there.