The evaluation of lactose intolerance begins with a history and physical exam.

Physical findings in someone with lactose intolerance may include:

• Abdominal bloating

Tests that may be used to evaluate lactose intolerance include:

• Elimination test:
• Eliminate dairy products from the diet and watch for symptom improvement
• Lactose breath test
• Lactose tolerance test
• Milk tolerance test
• Small bowel biopsy
• Colonoscopy:
• Allows a doctor to look inside, take tissue specimens, and remove any questionable growths or intestinal polyps.
• Upper GI endoscopy:
• Allows direct inspection of the stomach and duodenum