"routine PR" = routine rectal exam (PR = per rectum)
DRE = digital rectal exam
Although keep in mind that new prostate cancer screening guidelines don't have a hard and fast recommendation to perform DREs on every male over 40 like they used to. Too many false positives and associated morbidity from unnecessary biopsies and treatment. New guidelines simply recommend having a conversation with your patient and offering prostate cancer screening at age 50 for average-risk men and explaining the risks involved in screening as well the possible benefits. Even if they choose yes the American Cancer Society guidelines state they recommend "Screening with PSA with or without DRE."
Long story short, the number of 'routine DREs' is way down. May not be such a thing as "routine DRE" any more.
Moral of the story is that Ophthalmologists don't like the anus. Something for the pre-med original poster to consider as perhaps she may fare well with a career in Gastroenterology.
To the OP:
You'll find that in all fields of medicine there are evidence-based 'protocols' for how to handle various things. The art and challenge of medicine is in the cases that don't fit into those checkboxes, as well as knowing when the patient that looks like they fit into an easy cubbyhole really in fact doesn't. It's why it takes so long to be a trained physician.
Most of us like Ophthalmology because of the microsurgery. Precision surgeries with giant impacts for patients. We also enjoy the long term relationships that we have with patients. The kind of relationship that an Ophthalmologist has with their patients is unique among the surgical specialties. Most other surgeons don't see patients regularly throughout their lives like we do. It's a real privilege.
There are also headaches unique to Ophthalmology as there are with any field in medicine. As a premed though the biggest caution you should hear is that you need to make sure that there are some other fields of medicine that you might enjoy as well. Ophthalmology is very competitive, and getting into medical school in no way means that you will definitely become an Ophthalmologist. You need high board scores, good letters of recommendation, etc. Just be prepared that if this is a journey you want to take, it's going to be a long road of hard work to get there. But I think pretty much every Ophthalmologist will tell you that it was worth it in the end to be able to practice Ophthalmology.