**R10 — Abdominal and pelvic pain** is used when abdominal pain is the chief complaint without an identified cause. Anatomical sub-codes (R10.0 acute abdomen, R10.1 upper, R10.3 lower, R10.4 generalized) provide more specificity.
This is a transitional code — most cases are re-classified after workup (e.g., K59.0 constipation, N73.x pelvic inflammatory disease, K35.x appendicitis).
Belongs to **Chapter R** — Symptoms, signs.
