Have stool tests been done to rule out infective causes like parasitic or bacterial infection? Have you recently taken any de-worming medication? Can you elaborate more about your symptoms, the investigations done till date & the treatment received and about your eating habits like do you tend to eat at outside eateries & restaurants very often. Have you noticed symptoms flaring up after consuming any particular food item or liquids like milk, eggs, peanuts, food additives in restaurants, etc to rule out food allergy. Are you under stress due to other reasons as it can worsen your symptoms, if it turns out to be IBS.