Diarrhea and Nutrition

Patient: My daughter lives with her mother 3-4 days per week and myself 3-4 days per week. They are consecutive days. She has bouts of diarrhea that last one -two weeks 3-4 times per year. She also supposedly has diarrhea randomly at her mothers. I rarely see her like this at my house. Her mother has taken her to a Chiropractic Nutritionist who has tested her feces and says she is not alergic to anythig he tested for, however her “Total Intestinal SIgA(Stool)” is at 41 which supposedly means a low immune system. I guess normal is between 400 and 880(not sure the measurement) She is rarely sick( and what do the two things have in common?). The Doctor had also commented that this is a sign of possible Celiacs disease if something is not done about it. This Nutritional Chiropractor has eliminated everything from her diet (Gluten, cow milk, most other dairy, peanutbutter, sugar, Juice, Limited meats and eggs, eliminated most fats and oils besides olive oil)currently. I want to take my daughter for a second opinion and basically am unable to due to the fact that my Exwife has the insurance for her and says that I can not. Therefore I am looking for further information regarding this problem as well as suggestions. My daughter is 7 years old. Could there be other causes such as stress?