I have that as well as IBS.  Sometimes it is difficult to tell which one is bothering me.  I have medication for one but not the other.  A diet free from grains has been helping me for quite some time now.  It is hard to give up grains, but I have gut pain and muscle spasms when I regularly include them in my diet.  I wondered if anyone else has experienced this?  I have a high tolerance for pain, as well.  Hope you continue healing and are able to return to your regular activities.