According to the National Cancer Institute, a division of the governmental agency---National Institutes of Health (NIH)---bloating is commonly associated with or caused by intestinal gas, and described by people as a feeling of abdominal fullness. The institute further elaborates on the causes of bloating. Benign, or less serious conditions, which cause bloating include overeating, lactose intolerance, and constipation. When coupled with other signs and symptoms, bloating can also point to more serious conditions like ulcerative colitis, Crohn's disease and cancer.
Overeating
According to the "Stomach Capacity Reference" document published by the California Department of Public Health, an adult stomach can hold approximately 1 quart or 900 ml of food. This capacity is compared to the size of a softball, grapefruit or adult fist. The stomach will accommodate to an increased load after continuous abuse, and in a 1992 American Journal of Clinical Nutrition study analyzing bulimic subjects, findings show this can happen within a short period of time. A 2005 study published in Obesity Research, titled "Gastric Motor and Sensory Functions in Obesity," reviewed information that showed when the stomach was distended to hold volumes of food greater than 800 to 900 ml, feelings of fullness, bloating, pain, and even nausea and occasional retching would regularly ensue. Overtime, the stomach would accommodate to hold this extra volume and the symptoms would subside.
Food Intolerance
The American College of Gastroenterology consumer health guide on "Food Intolerance," considers common food intolerances to include those of lactose, a sugar in dairy products; gluten, a protein in wheat, barley, oats and rye; and corn. Enzymes are used in the digestive process to break larger molecules into those that are smaller and easily absorbable. Lactase is an enzyme required to break the milk sugar lactose down and allow its absorption. The National Digestive Diseases Information Clearinghouse (NDDIC) portends that lactose intolerance is experienced when dairy products are eaten by those people who totally lack or have very low functioning levels of the lactase enzyme. According to the NDDIC, deficiency of the lactase enzyme is common in people of African, Asian, Native American, and Mediterranean descent. The symptoms associated with lactose intolerance include excessive gas, bloating, flatulence, cramping and floating and foul-smelling stools. The consumer health guide continues on to describe how undigested food particles remain in the large intestines and bacteria inherent to the gut feed off them, producing gas accordingly. The gas that accumulates in the abdominal area is described as bloating.
Constipation
The NDDIC defines constipation as having fewer than three bowel movements per week. It is one of the most common gastrointestinal complaints in the US, explains the NDDIC document, with more than four million Americans experiencing frequent constipation. When stool is not moved out of the digestive tract, it accumulates, becomes compacted and can cause distension of the abdomen.
PMS
Premenstrual associated bloating is thought be caused by dominant levels of estrogen as compared to its balancing hormone, progesterone. Aldosterone modulates water and sodium balance in the body. Medical herbalist, Chanchal Cabrera, MNIMH, AGH, in her article "Female -- Premenstrual Syndrome," published in the clinical journal Medical Herbalism comments that women with PMS associated bloating were found to have elevated levels of aldosterone, brought on by both high levels of estrogen and stress and lower than normal levels of magnesium.
References
- Medical Herbalism: "Female-Premenstrual Syndrome"
- National Cancer Institute: Definition -- "Bloating"
- Obesity Research: "Gastric Motor and Sensory Functions in Obesity
- California Department of Public Health: "Stomach Capacity References"
- American Journal of Clinical Nutrition: "Gastric capacity, gastric emptying, and test-meal intake in normal and bulimic women"
