10yr old protruding belly

I have a 10 year old daughter who is always having stomach aches. She is average to thin in size everywhere except for she has this a protruding abdomen. She is otherwise a healthy kid. as she gets older her belly gets bigger and she is made fun of in school. Diabetes is in my family... my father and grandfather developed it later in life.
Tonight my daughter is in some pain and has diarrhea. Her stool is a bright orange red and almost jelly like. She has no fever and no other symptoms. After having a BM she is back to playing with her puppy and enjoying life. She is a good eater but enjoys spicy foods sometimes to the extreme. If you look at my picture it is of my two daughters the one in blue is 12 and the one in red is the 10yr old with the problems. Please help if you can..

[Ratnakar Kini, MD]

Hi,
Has she been evaluated for celiac disease?