It this film oil or more likely mucous? (pic of water included)

[runaway2005]

Hello, I'm a 25 year old male, who is at an optimal BMI, and has no known diseases. I am lactose intolerant as far as I can tell. I've noticed I get floating stools once in awhile. They are normal in color, don't smell foul etc and I don't seem to have issues/stomach aches when I eat high fat foods. I have noticed what appears to be a sort of film on top of the water after going. It wasn't extremely noticeable unless I got close and looked, and I had to find the right light for it to show up in the pic. Link to picture of the water: http://imgur.com/a/HY2vr  When I took the pic, I didn't have floating stool, it was normal in color etc. I'd assume if I wasn't absorbing fat properly the issues would be more noticeable than non floating stool with some sort of film on top of the water? I asked someone else and they said this looked normal, but I want to double check if it's something I should have looked into. I have noticed mucous in my stool recently sometimes, and due suffer from constipation bouts once in awhile (not really currently though) and I had a colonoscopy (unrelated, but a barium x-ray as well) due to a family history of colon cancer (great grandpa had it), which came back with no issues. Do you think this is oil, or most likely either normal/common or mucous? I would greatly appreciate your thoughts.

[JErik16]

Did you ever get to the bottom of this ? Experiencing the same thing

[runaway2005]

I consumed a fair amount of fat yesterday (sort of to test how well I handled it) and didn't notice any floating, yellow/pale color or oil droplets. I saw this sheen again, but even way less this time. I did have somewhat loose stool/also somewhat formed. I think it's probably mucous what I'm seeing, but would appreciate any thoughts if it could be something else.