I have a pain on my left buttock it make it difficult for me to sit and walk or run. what can it be?

Buttock pain: This may be ischiogluteal bursitis, an inflammatory process causing buttock discomfort. Try taking anti-inflammatory medication like ibuprofen or naproxen for a week or so, avoid sitting on hard surfaces, and stressing the buttock area. Gentle stretching may help. An orthopedic specialist is best qualified to evaluate and treat you. Sometimes a corticosteroid injection is recommended for this prob