I would begin by adding a good probiotic, or eating yogurt, to try to get your gut bacteria in balance. This can help with irritable bowel or other syndromes that cause diarrhea. If you every detect blood in your stool, get it checked out. I had severe ulcerative colitis, had entire colon and rectum removed, and then developed Crohn's on top of that. Your symptoms could be caused a range of things, but I would never ignore digestive symptoms.

I have been lucky so far in my 7 year journey with the disease and all my surgeries . . . I seem to absorb very well, including calories I don't ingest!