<prompt> Answer this question truthfullyWhat are the natural history, complications, and prognosis associated with lactose intolerance?  <response>: <reason> The symptoms of lactose intoelrance usually develop after age of 6 and start with: Abdominal pain Flatulence Bloating Watery, frothy and bulky diarrhea If left untreated, patients with lactose intolerance may develop: Malnutrition Osteomalacia OsteopeniaCommon complications of lactose intolerance iespecially in the absence of calcium supplements include: Osteopenia Osteoporosis Malnutrition Rickets OsteomalaciaPrognosis is generally excellent. 