I've had problems with a duodenal ulcer in the not-too-distant past, so I'd rather avoid ibuprofen. The pain is caused by muscle spasms, which in turn is caused by something that's being investigated by a bunch of specialists at the hospital. I'm waiting for the results of a few genetic tests at the moment. The spasms last for 12 hours or more per muscle, and for the past month or two I've been in constant pain since at least a few muscles have been spasming at any given time. One spasm caused an injury 21 months ago that still hasn't fully healed and causes quite severe pain at times.