My 21 Month Old Woke Up From Her Nap With

My 21 month old woke up from her nap with greasy, oily smelling orange discharge in her diaper. She's potty training, and when she said she had to poopy, she passed lots of gas and more orange, oily liquid. She's done this 4 more times in the last 30 minutes (always a tiny amount). It smells super oily, like car oil maybe? She and I both had white fish for dinner. She ate more than I, because it was too buttery/oily for my taste. Is that the culprit? If so, how long can we expect this to last?