Our review shows that high-quality studies on the diagnosis of lactose malabsorption and intolerance in primary care are urgently needed. An important prerequisite would be to clearly define the concept of lactose intolerance, as well as how it should be assessed.

SUMMARY BackgroundDespite the trend towards making a positive diagnosis of irritable bowel syndrome (IBS), many health care providers approach IBS as a diagnosis of exclusion.

Although calprotectin and ultrasonography showed consistent and promising findings, none of the studies was performed in primary care. To assist primary care physicians in diagnostic decision making, we urgently need high quality studies performed in primary care.