osteoarthritis
"Works wonders on lower back pain but sometimes needs a narcotic pain killer or muscle relaxer for days when pain is more severe.  Downside of this drug is that taking too much causes excruciating abdominal cramping and stabbing gas pains in the intestines.  But it's an 8-hour pill, so pain relief usually lasts and it is not hard to space doses out since it lasts so long."