For temporary relief from gas, you can take over-the-counter Simethicone. For the lower abdominal and back pain, an anti-inflammatory pain reliever like Ibuprofen or Acetaminophen may help, especially if the pain is related to your menstrual cycle or digestion. However, because combined lower abdominal and back pain can stem from various sources such as urinary tract infections (UTIs), pelvic inflammatory disease, or gastrointestinal issues, it is crucial to get a proper diagnosis. Please consult a doctor for a physical exam. Seek immediate medical attention if you experience severe pain, fever, nausea, vomiting, or changes in urination.