Distended lower abdomen and liquidy diarrhea

My 17 1/2 month old daughter's lower abdomen looks swollen/distended today. It sticks out beyond the normal under three distention that all babies have and is harder but at the same time oddly more squishy than the rest of her abdomen (not really sure how to explain it). She also has had mucous diarrhea all day, with about a diaper an hour. She has had very little appetite and hasn't wanted to sleep. Other than this, she seems fine. She is her normal happy go lucky self. She is done teething (has all of her teeth except the 2 year and beyond molars) and does not have a fever. Is this something I should be concerned about?

Does she have a cold? Post nasal drip?

The mucous in the stool would be what concerns me. Other than that as long as she is not dehydrated (still crying tears, moist mouth) then it is no worries. If it lasts more than a couple days bring her in.

Until then try the BRAT Diet, it is intended for diarrhea.(Bananas, Rice, Applesauce, Toast.)