 [ Symptoms ] bowel movements r fatty slimy and greasy and float yuck  blood wk for celiac disease negative can you help [ Disease ] so first i was wondering if this might have something to do with your diet because i remember this was a side effect of 1 eating olestra fat free chips and 2 some of the weight loss medications then i looked to see why this happens and the explanation was malabsorption here is an older article on olestra but it gave me lots of good information hope this helps