I would suggest looking up Irritable bowel syndrome. i have the same symptoms you do and that's what they told me it was. i know what a pain it can be. spiffee
Maybe check out information on Coeliac Disease which can give the same symptoms. Good luck
Have you ever researched irritable bowel syndrom?? Its the most commonly diagnosed intestinal problem, and its usually only diagnosed when someone has symptoms like yours, but all medical tests come out normal. The mucus is common in irritable bowel syndrom as well. You should look it up on the net. Its also known to cause alternating constipation and diarreah. Its not life threatening, but it can be a really annoying and painful.