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Motility in the small intestine

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Motility in the small intestine
The fed (or eating) pattern of motility

Segments that make up the small intestine are the duodenum, jejunum and ileum. The common factor among these segments is the main function of breaking down the food content into smaller particles with the aid of digestive enzymes and absorption of the resulting nutrients.
During and after a meal, irregular or unsynchronized contractions of the smooth muscle moves the food content back and forth to mix it with the digestive juices. The content moves slowly towards the large intestine while digestion and absorption take place.


Segmentation Contractions

the alternating and uncoordinated contraction of the inner circular muscle causes contraction in isolated segments of the intestine and contributes to digestion by promoting mixing, churning, grinding and absorption of nutrients by exposing the food particles to a larger surface area. There is no propelling movement in this type of contraction. This type of contraction may be visualised as a string of sausages. Segmentation contractions divide a bolus of food and allow it to move back and forth to enhance mixing, digestion and absorption.

This type of contraction occurs in the small intestine to enhance the process of mixing, digestion and absorption of nutrients.

In the Colon this type of contraction is responsible for the formation of faeces and movement of content towards the rectum. Segments in this area are called Haustra and promote absorption of water and electrolytes from the contents, leading to the formation of faeces.

Migrating Motor Complex-the growling sounds from your bowel

this is a sweeping peristaltic wave that goes through the GI tract once every 90 to 100 minutes and occurs in-between the times when there is no consumption of food (Fasting state).

The main function of this wave is to clear any residual chyme and undigested material from the stomach. This wave begins in the stomach and continues throughout the small intestine.

The contraction wave can last from 5 to 15 minutes and during this time the pyloric sphincter remains relaxed and open to allow residue to pass freely into the small intestine. There is also an increase in secretion of bile and pancreatic juice during this increased motility and probably aid in the cleansing and removal of bacterial population from the small intestine.

This type of motility is controlled via the central nervous system via the local release of the hormone Motilin.  Motilin is secreted into the circulation during the fasted state at intervals of roughly 90 to 100 minutes and contributes towards the control of smooth muscle contractions in the upper gastrointestinal tube.

Ingestion of food tends to abolish the migrating motor complex and allows normal digestive pattern motility to resume. This explains why you are able to stop the noisy growling sounds from your “tummy” by eating some food.

Gastroenteric reflex

Mechanical distention in the Stomach and duodenal cavity is sensed by the enteric nervous system and leads to muscle contractions that may lead to evacuation of the bowel.


Gastroileac reflex

this is the reflex that relaxes the Ileocecal valve and allows the contents of the ileum to enter the Cecum-triggered by the presence of food (your next meal) in the stomach. Gastric activity increases activity in the ileum.

The Ileocecal valve is located at the last few centimetres of the ileum and its function is to control the flow of contents from the ileum into the Cecum, which is the beginning of the large intestine where faeces are made. This valve functions as a one way valve and does not allow the backflow of material once it has left the ileum, although Straining during defecation is known to cause the valve to malfunction and allow Bacteria from the Cecum to enter the ileum and cause infection which then promotes fermentation of food content instead of digestion and absorption of nutrients (small Bowel Bacterial overgrowth).

The valve normally slows the flow of chime into the Cecum to allow for maximum absorption of nutrients from the ileum. Control of the valve is related to mechanical distention which is created by the presence of large volumes of content. Ileal distention or stretching opens the sphincter and stretching or distention in the colon closes it.

 

 

How to heal and prevent Bowel disorders

Diet is not about what you should NOT eat, it’s about what you should include in the diet that matters.
As long as your diet includes the correct balance of plant foods containing soluble fibre, insoluble fibre and resistant starch your colon will produce the perfectly formed stool. The important next step is to evacuate this stool without straining so that the body does not suffer from the pressures created each time the bowel is emptied.

In order to heal and prevent bowel disorders you need to make lifestyle changes that last the rest of your life time.

1. Include more fluids and plant food containing soluble fibre, insoluble fibre and resistant starch in the diet so that the perfectly formed stool will be made in the colon and beneficial bacteria will flourish and eliminate disease causing bacteria and fungi.

2. Evacuate the perfectly formed stool by adopting the squat posture to eliminate the need to strain during bowel movements.

It is not possible or safe to squat on the modern raised toilet seat installed in all western homes and it is impossible to squat for any length of time if you have not done this from childhood onwards. This makes the use of any raised platforms impossible to adapt to.

The SquattLooStool is designed to allow you to adopt the squat posture while seated comfortably on your raised toilet seat. The single best and easiest lifestyle change you will ever make, leading to a healthier body.