Bush Beats Vol-5, No-3, 2019

Functional bowel disorders comprise a spectrum of chronic gastrointestinal (GI) disorders characterized by abdominal pain, bloating, distention, and/or bowel habit abnormalities (constipation, diarrhea, or mixed constipation and diarrhea) in the absence of any organic or biochemical pathology.1,2 These are primarily attributed to the deranged functioning of the well coordinated brain-gut axis that results in an array of symptoms that can affect any part of GI tract.3 Irritable bowel syndrome (IBS) is a highly prevalent functional bowel disorder characterized by symptoms of abdominal pain or discomfort that occur with changes in bowel function (Box 1).4-6 Based on stool consistency, the Rome IV criteria classify IBS into constipation-predominant IBS (IBS-C), diarrhea-predominant IBS (IBS-D), IBS alternating between constipation and diarrhea (IBS-M), or unclassified IBS (Box 2).

Lactose intolerance, defined as experience of gastrointestinal symptoms following the intake of lactose- containing food products, is the most common problem limiting milk and dairy products consumption worldwide.1 Individuals with lactose intolerance exhibit an inability to digest significant amounts of lactose due to deficiency of the intestinal lactase enzyme.2 Due to this, dietary lactose does not get broken down into glucose and galactose and the unabsorbed lactose is metabolized through a salvage pathway by colonic bacteria to produce short-chain fatty acids and gas, mainly hydrogen (H2), carbon dioxide (CO2), and methane (CH4). The gas distends the intestines and likely explains the clinical syndrome that manifests with a range of gastrointestinal symptoms including abdominal cramps, bloating, and flatulence.3-6 Moreover, undigested lactose creates an osmotic load that draws fluid and electrolytes into the intestinal lumen, often resulting in loose stools or osmotic diarrhea