A 52-year-year-old woman presents with crampy abdominal pain and intermittent diarrhoea for 1 year. She reports that symptoms often worsen with stress. There is no weight loss, rectal bleeding, nocturnal diarrhoea, or family history of colorectal cancer or inflammatory bowel disease. Physical examination and basic blood work including C-reactive protein are normal. According to Canadian IBS guidance, what is the most appropriate next step?