It is very common that some people will experience left sided back pain more frequently than the right side. This kind of pain can last for days, weeks and sometimes months. The location of this pain is usually below the ribs and around the side of the torso. This dull like and aching pain is usually more intense during particular hours of the day. Some people are very sensitive to touch in that area and some are sensitive to the dietary changes. Exercises, deep breaths and bowel movements can affect the pain on a left side of the lower back as well.