In lieu of a full low-FODMAP diet, a lactose-free diet could be empirically tried, even in patients with no known lactose intolerance. Gastrointestinal reactions to lactose-free dairy or very low levels of lactose may be due to a milk protein allergy rather than lactose intolerance. [1]
Some patients may find gluten avoidance improves some of their symptoms. “Non-celiac gluten sensitivity” is used to describe patients who have gluten sensitivity but do not have celiac disease. In IBS-D, this improvement may be due to reduction in consumption of fructans, rather than gluten, as both are present in similar food items.[2][3]