|MadSci Network: Medicine|
The actual gases are fermentation products of the action of bacteria on the food and discarded bodily products - dead red cells, intestinal lining cells, fluid secretions ,and the like, as they pass through. Mostly, these gases are carbon dioxide, methane, some hydrogen sulphide( hence the smell) and other chemically "reducing" gases. Many of these microbes are anaerobes, which means that, like the earliest inhabitants of Earth, they do not breathe oxygen, but prefer to live in an oxygen poor or free environment. Solids are moved through the gut by successive waves of alternating contraction and dilatation, called peristalsis. This type of action can be observed in earthworms as they move, or snakes as they swallow whole prey. If the peristaltic waves are more frequent or intense, relative inco-ordination can result in pockets of gas under increeased pressure. As these bubbles make their way through the gut's fluid contents, bubbling sounds like those in a Turkish pipe occur, which you perceive as borborygmi. Certain foods, eg spices , can stimulate the gut to overact, and produce borborygmi, or again since the peristalsis is caused by muscles under nervous control, anxiety or stress can produce similar results. Some people are oversensitive in this area, and have so-called irritable bowels. Further build up of pressure leads to local stretching/dilatation of the bowels locally, which can be intensely painful( stomach cramps, colic etc). Infection by foreign microbes, eg cholera, typhoid can set up inflammation of the bowel lining which in turn may increase gas production, and peristaltic activity- so much so that products miss out on the final water extraction, and appear as diarrhoea. Then again locally inactive gut - perhaps replaced by polyps or tumours, might set up irregularities in the peristalsis in turn leading to borborygmi , but there are usually other features such as bleeding or weight loss to give the game away. For the ordinary borborygmi, not caused by serious pathology, good advice is a well varied diet, with due time allowed for its enjoyment and digestion. A good admixture of roughage/fibres, as cereals or bran or the like, is advised to even out the pressure within the gut by giving something solid and consistent for the peristalsis to work on, and should reduce this problem Hope this helps, Yours sincerely, Michael Martin-Smith
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