Yes, Etorica-90 Tablet (Etoricoxib) may help relieve lower back and hip pain, as it is an anti-inflammatory medicine that reduces pain and inflammation in joints and muscles. However, it should be taken only for short-term relief and after medical advice. Take it once daily after meals to help prevent stomach upset. Do not combine it with other painkillers such as ibuprofen or diclofenac, and avoid using it if you have heart disease, kidney problems, stomach ulcers, or uncontrolled blood pressure. If your pain persists for a few more days or you develop symptoms such as leg numbness, please consult a doctor for proper evaluation.

Persistent back pain for 15 days despite medication needs a proper medical evaluation rather than continuing treatment on your own. You should see a doctor for a physical examination and possibly imaging tests to identify the underlying cause. Seek urgent care if you notice warning signs like leg weakness, numbness, or changes in bowel or bladder control. Until you are examined, try to stay gently active with light walking and avoid heavy lifting and prolonged sitting to prevent further stiffness.

Your waist and knee pain are unlikely to be directly caused by gastritis (inflammation of the stomach lining) and may be due to a separate musculoskeletal issue, such as strain, poor posture, early arthritis, or vitamin D deficiency. If you have been taking painkillers like ibuprofen for gastritis-related discomfort, they may sometimes worsen stomach symptoms and are not ideal in this situation. You can consider paracetamol for pain relief, maintain gentle physical activity, and follow a light, non-irritant diet for your gastritis. If the pain persists or worsens, please consult a doctor for further evaluation and treatment.