After drinking milk and other lactose-containing beverages, you can find out if you are lactose intolerant through daily observation or by going to a regular clinic for urine galactose test and lactose hydrogen breath test.
1. Daily observation: After drinking milk, observe whether you have any abdominal discomfort, such as rumbling, colic, diarrhea, etc. If you have any of these symptoms and stop drinking milk, you should take a lactose intolerance test at the clinic. If you have these symptoms and they are relieved soon after stopping the use of lactose-based foods, you can assume that lactose intolerance exists. Generally speaking, lactose intolerance symptoms are not very serious and may worsen with time.
2. Urine galactose test: This method measures the level of galactose in the urine, reflecting the activity of lactase. If the galactose test is pale or does not show any color, it can be judged as lactose intolerance.
3. Lactose Hydrogen Breath Test: If lactose is not completely broken down by enough lactase, hydrogen will be produced under the fermentation of intestinal bacteria, and part of the hydrogen will be exhaled through the lungs. If the difference between the peak concentration of exhaled hydrogen and the basal value is more than 20PPM within 3 hours after lactose intake, it can indicate the existence of lactase deficiency, i.e. lactose intolerance.
If you are lactose intolerant, it is recommended to consume as little lactose-containing food as possible, and to choose other similar foods instead under the guidance of a physician to ensure nutritional enrichment.