How can i tell if i have fructose intolerance?

Symptoms/test.: This has symptoms like bloating, diarrhea and/or constipation, flatulence, and stomach pain. This has a diagnostic test called a hydrogen breath test and is the current test used for a clinical diagnosis. Fructose is given and, if not absorbes, is metabolized by bacteria that gives off hydrogen and methane. This is detected and anything higher than 12-15ppm is positive, typically 20ppm.