What Causes Frequent Pain In Lower Back?

Hello, I have been frequently feeling a sharp pain in the lower back above the buttocks on the right hand side of my body. I have feelings in the front of my body in the groinal area on the other side of where the pain is on my upper buttocks area. I just had a bowel movement and the fecies are just small pieces not like the larger stools that I usually have. My stools have been like that today and recently. The lower back sensations have been coming once in awhile but they seem to be getting more severe than earlier.