Frustrated and ready for answers - Crohn's disease/UC?

A month ago, I began having explosive diarrhea. I had my gallbladder removed 2 years ago and while ocassional diarrea (diarrhea) was normal, this was different. I was hospitalized for a week. Without being too graphic - my stools were all water (and a clear yellow color) with small particles mixed in.  My liver function was down. I was checked for C. diff which came back negative. An upper scope revealed the food I ate 16 hours before was still in my stomach. I was recently checked for gastroparesis and the test came back positive. However, I'm still having terrible, horrible belly pain on my left lower side at belly button level. The pain is also in my back. It is so debilitating I cannot sleep for more than five minutes without it waking me up. My stools are very loose with mucous and blood mixed in. In the past two days I have lost 10 lbs. My gastro asserts it is probably just community aquired gastrointeritis. I am convinced it is something more. I'm am on Cholestid, which is supposed to bulk up my stools. It hasn't. I guess logic tells me that if my stomach is slow, wouldn't that make me constipated? And if the stomach and intestines are not related - isn't there something else going on? My research has produced little evidence that gastroparesis can cause diarrhea. Has anyone else had similar problems? I am scared to eat and can't imagine going through one more day with this crampy, sharp pain and diarrhea.