Thanks for the additional information.
Well, with a normal colonoscopy and bowel studies, the most likely cause for this would be Irritable bowel syndrome- of the diarrheal variety.
Diet Triggers for IBS Diarrhea
Some foods can worsen IBS-related diarrhea. These include:
Too much fiber, especially insoluble fiber found in the skin of fruits and vegetables
Food and drinks with chocolate, alcohol, caffeine, fructose, or the sugar substitute sorbitol
Fried and fatty foods
Food and drinks with dairy
Foods with wheat -- Some people may be allergic or have a negative reaction to gluten
Eat a moderate amount of soluble fiber. It adds bulk to the colon and can help prevent spasms. Good sources are whole wheat breads, oats, barley, brown rice, pasta, the flesh of fruit (as opposed to the skin), and dried fruits.
Don't consume foods with extreme temperatures, such as ice-cold water and steaming hot soup, in the same meal.
Stay away from broccoli, onions, and cabbage. They can cause gas, which can make diarrhea sufferers feel worse.
Eat smaller portions.
Drink six to eight glasses of plain water a day, but drink the water an hour before or after meals, not with meals.
That being said, another common cause of diarrhea and cramping is lactose intolerance. I would consider cutting out dairy, with the exception of yogurt and cheese (as it has digestive enzymes)
If this doesn't help, then make the appointment to see the GI doctor.
I hope that this helps!
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