Hello, Thanks for your query, Irritable Bowel syndrome is functional disease of GIT presents with nausea, vomiting, abdominal bloating , abdominal distention,diarrhea, constipation, flatulence and anxiety. It is diagnosed by excluding all other condition that may present similar way, like gastroenteritis specially Giardia lamblia,celiac disease , H pylori etc Avoid food and drinks like tea that may predispose symptoms. Take large amounts of wwater. You are advised to visit your doctor and get stool analysis/culture, upper GI endoscopy, colonoscopy, blood tests, Ultrasound to reach a proper diagnosis. Hope it helps. Take care!