You may want to go to a colorectal doctor. They specialize in the rectum and anal area. Gastroenterologist do not. I have had 5 colonoscopies in the last 10 years. They saw nothing. I finally was tested for Celiac, an autoimmune disease of the intestine that is genetic. Having to go Gluten Free has been hard. Food was a big part of my traveling and cooking. But the painful problem I have now is in the anal sphincter muscles. I may have an anal fissure. Standing or walking is bad as well as sitting. It is 24 hours now. I am waiting for the colorectal Dr. To call me. Before I had the Celiac diagnosis they all said I had IBS or pelvic floor dysfunction. None thought of Celiac. It has not been researched a lot and most dr. Do not even know of it. They did think it was a peudendal nerve problem and I had dozens of nerve blocks. The problem is it is very hard to access it because it is at the bottom of the spine and is almost hidden. My town of Redding does not have a doctor who knows Celiac for 100 miles. I am not sure your symptoms are in the over 200 listed. Check Mayo Clinic on the internet. I had a PN test and it just about killed me. It was definitely painful, so it could have been inflamed. Look under colorectal doctors to see their specialty’s . I also have many other genetic problems. I have used 5% lidocaine, but think it is burning now. Good luck. The doctors don’t want to treat people with difficult problems. That is why a clinic like the Mayo Clinic is good. We only have one in the west, Phoenix. There are several in the east. The university of Chicago and Cleveland Clinic have team treatments.