Low right side pain twords back?

Some possibilities. If one has very uncomfortable tummy pain, and is normally in good health, plus is not pregnant, the possibilities include: appendicitis (usually has fever), gall stones, kidney stone (very painful), constipation (crampy), stomach flu, etc... Most people with "moderate pain", meaning more than mild pain, need a doctor's evaluation to be sure it is not appendicitis, which would need surgery.