There is an excellent wikipedia page about the the procedure called tonsillectomy: "Although tonsillectomy is performed less frequently than in the 1950s, it remains one of the most common surgical procedures in children in the United States and many other western countries."
That WP page is amply sourced with research papers, the following box is just a ...
After removal of tonsils, most adults
have significant pain for 10 -14 days, some up to 3 weeks. Because
adults & teenagers have larger tonsils and more developed throat muscles, pain and muscle spasm can
make it difficult to swallow for 2 weeks or more. Constipation may occur because narcotic pain
medication, when taken regularly, can slow ...