Small Intestine

Definition of Small Intestine:

The small intestine lies between the stomach and the large intestine.  It is about 6 meters (20 feet) long and its primary function is to digest (break down) food and absorb nutrients (vitamins, minerals, proteins, carbohydrates, and fats).  The small intestine makes up more than 70% of the length and 90% of the surface area of the gastrointestinal (GI) tract.

Also: Small Bowel

Topics Related to Small Intestine

Alfalfa a treatment
“...Research suggests that it may inactivate dietary chemical carcinogens in the liver and small intestine before they have a chance to do the body any harm...”

Atrophic Gastritis

...the condition
“...Ingested bacteria can thus survive and reside in the stomach and the upper part of the small bowel.  This problem affects approximately 20% of people between 60 and 69 years of age, and 40% of people over 80...”
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More topics Related to Small Intestine

Bacterial Dysbiosis

...the condition
“...Fermentation / Small Bowel Bacterial Overgrowth (SBBO)...”
...recommendation Antibiotics
“...Where contamination of the small bowel by anaerobes is the problem, metronidazole or tetracyclines may be beneficial...”
...recommendation Probiotics
“...It has been found to be an effective adjunctive treatment for control of symptoms associated with small bowel dysbiosis in a number of patients...”


...related topic
“...Bile is stored in the gallbladder and is released when fat enters the first part of the small intestine (duodenum) in order to aid digestion.”

Carbohydrate Intolerance

...the condition
“...This type of starch cannot be digested by the small intestine and so passes into the large intestine, where it is broken down...”

Carcinoid Cancer

...the condition
“...The commonest sites of the primary tumour are the appendix (30%), small bowel (20%), colon (20%) and stomach less than 10%...”

Celiac Disease

...related topic
“A digestive disease that damages the small intestine and interferes with absorption of nutrients from food...”


...related topic
“A digestive enzyme secreted by the pancreas into the small intestine which breaks down polypeptides or proteins.”

Coffee Enema a treatment
“...It is the liver and small bowel that neutralize the most common tissue toxins: polyamines, ammonia, toxic-bound nitrogen and electrophiles...”


...related topic
“...The colon takes the contents of the small intestine, moving them to the rectum by contracting.”

Consequences of Gallbladder Surgery

...the condition
“...When you eat, the gallbladder contracts, emptying its contents into the small intestine, where the bile mixes with the food...”

Crohn's Disease

...the condition
“Alternative names: Regional Enteritis, Ileitis, Inflammatory Bowel Disease (collective term for Ulcerative Colitis and Crohn's Disease), IBD Crohn's Disease causes inflammation in the small intestine.  Crohn's disease usually occurs in the lower part of the small intestine, called the ileum, but it can affect any part of the digestive tract, from the mouth to the anus...”
...relationship to Small Intestine Cancer
“Adenocarcinoma of the small bowel is associated with Crohn's disease, which usually occurs in the lower part of the small intestine (the ileum)...”
...recommendation Sugar Avoidance / Reduction
“...Yeast and bacteria can then overgrow in response to these newly available nutrients, increasing toxic by-products and mucus production, resulting in further injury to the small intestine and malabsorption...”
...recommendation against Glutamine
“Although glutamine is known to play a role in small intestine function, in Crohn's disease at least two studies have shown it to be mildly harmful...”

Cryptosporidium Infection

...the condition
“...After entering the host, these Cryptosporidia make their way to the small intestine and attach to the walls of the intestines where they multiply and at a later stage spread even further by leaving the host in massive numbers by being shed in its feces...”


...relationship to Short Bowel Syndrome
“Short bowel syndrome is a malabsorption disorder in which water and nutrients are not properly absorbed because a significant portion of the small intestine is missing...”


...the condition
“...A diminution in peristaltic activity and dilation of the lower esophagus and small intestine may be present...”

Diabetes Type II

...recommendation Cinnamon
“...The mechanism is not clear, but is thought that cinnamon either slows stomach emptying and/or blocks digestive enzymes in the small intestine that break down carbohydrates.”


...the condition
“...Frequent, small-volume bowel movements typically are associated with diseases of the left colon or rectum, and watery large-volume diarrhea suggest disorders of the small bowel or proximal colon...”

Digestive Enzyme (Trial) a treatment
“...Plant-derived enzymes operate effectively at a very wide pH range, digesting actively in the acidic environment of the stomach and the alkaline environment of the small intestine.  Pancreatic enzymes improve digestion and assimilation of proteins and other nutrients as well as reducing circulating immune complexes that cause antibody and autoantibody formation...”

Digestive Enzyme Need

...the condition
“...Usually secreted by the pancreas into the small intestine, digestive enzymes are those which help to breakdown the food we eat, continuing the digestive process which began in the stomach...”

Diverticular Disease

...the condition
“...Rarely, diverticula may also occur in the stomach or small intestine.  Diverticulosis used to be a rare disease and even today it is almost nonexistent in certain parts of the world...”


...related topic
“First portion of the small intestine between the pylorus and jejunum, connecting to the stomach.”

Dyspepsia / Poor Digestion

...the condition
“...Dumping Syndrome: Rapid gastric emptying caused by the lower end of the small intestine (jejunum) filling too quickly with undigested food from the stomach...”


...relationship to Bacterial Dysbiosis
“...Evidence of small bowel dysbiosis and subtle malabsorption phenomena was found in the majority of cases.”

Elevated Bilirubin Levels

...the condition
“...Increased bilirubin levels may be due to liver disease (such as hepatitis), blood disorders (such as hemolytic anemia), or blockage of the bile ducts through which bile flows from the liver to the small intestine.  An allergic reaction to the blood received during a transfusion can also cause the levels of bilirubin to rise in adults...”


...related topic
“...Enteric-coated: A coating that prevents a tablet or capsule from being digested until it reaches the small intestine.”


...the condition
“Enteritis means inflammation of the intestinal tract, especially of the small intestine.  Serious complications may occur, especially in infants and the elderly...”


...related topic
“...It contains the stomach, liver tip, pancreas tail, duodenum, spleen, adrenal glands, transverse colon, small intestine, the left and right kidneys, and the left and right ureters.”

Excess Sugar Consumption

...the condition
“...These wholesome foods break down slowly into small units of glucose that enter the bloodstream through the small intestine, where they are burned smoothly and gradually as the body requires the energy...”

Gallbladder Disease

...the condition
“...Bile helps digest fats as they pass through the small intestine.  Bile is either released from the liver directly through ducts into the small intestine, or is stored in the gallbladder for later release...”
...our question about 'rotten egg', 'eggy' or 'sulfur-tasting' burps
“If you suffer from sulfur burps and gas you may have a problem in the gallbladder or small intestine.  Rotten egg burps are caused by hydrogen sulfide gas which is produced by gut bacteria when certain types of food pass through the digestive system...”

Gastric Dumping

...related topic
“A condition where food passes too quickly through the stomach and enters the small intestine still largely undigested.”

Gastric/Peptic/Duodenal Ulcers

...recommendation Glutamine
“...The amino acid glutamine works over time in doses as low as 500mg three times daily (for one month) to heal stomach and small intestine lesions.  A study of ulcers found that 1600mg of glutamine per day had a 50% cure rate within 2 weeks and 92% within 4 weeks.”

Gastrointestinal Bleeding

...the condition
“...such as different types of X-rays and/or endoscopy, depending on whether the doctor suspects that the bleeding is coming from the upper digestive tract (esophagus, stomach, and first segment of the small intestine) or lower digestive tract (lower small intestine, large intestine, rectum, and anus)...”
...our question about Black, tarry stools
“Black, tarry stools usually result from bleeding that occurs high up in the digestive tract – for example, in the stomach or first segment of the small intestine (duodenum); blood in the stomach turns black when exposed to stomach acid and enzymes...”

Giardiasis Infection

...the condition
“...The low pH in the stomach and pancreatic proteases found in the proximal small intestine promote rapid breakdown of the cysts' outer walls within minutes of reaching the duodenum...”
...recommendation Prebiotics
“...Prebiotics possess limited ability to alter the small bowel ecosystem and most likely have no effect in the proximal section of the small bowel where giardia resides...”
...recommendation Probiotics
“...Orally-administered probiotics have great potential to affect the microflora of the proximal small intestine as this area is sparsely populated when compared to the colon or distal small bowel...”
...recommendation High/Increased Fiber Diet
“...When infected animals on the low-fiber diet were put on the high-fiber diet, trophozoites were cleared from the small bowel.  The number of trophozoites attached to the jejunal epithelium decreased, while the number associated with the mucous layer increased...”
...recommendation Low/Decreased Fat Diet
“...Dietary fat is also the main stimulator for the release of bile acids into the intestinal lumen, which giardia trophozoites depend on for survival in the small bowel.”
...recommendation Dairy Products Avoidance
“Studies have shown that giardia infection, whether symptomatic or asymptomatic, can reduce the production of lactase in the small intestine, resulting in lactose malabsorption and its resultant diarrhea...”

Gluten Sensitivity / Celiac Disease

...the condition
“...Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food...”
...relationship to Small Intestine Cancer
“Adenocarcinoma of the small intestine and lymphoma of the small intestine are both associated with celiac disease.”
...recommendation Glutamine
“Glutamine is the preferred fuel of small intestine cells.  Supplemental glutamine may promote a faster recovery time once a gluten-free diet is begun.”
...recommendation Gluten-free Diet
“...Improvements begin within days of starting the diet, and the small intestine is usually completely healed in 3 to 6 months...”


...related topic
“Hookworms average about 25 of an inch (10mm) in length and live in the small intestine of the host...”

Hookworm Infection

...the condition
“...Hookworms average about 10mm in length and live in the small intestine of the host...”

IBS (Irritable Bowel Syndrome)

...the condition
“...The colon, which is about 6 feet long, connects the small intestine with the rectum and anus...”
...relationship to Bacterial Dysbiosis
“Some bacterial infections of the small bowel increase passive intestinal permeability...”


...related topic
“Pertaining to both the last section of the small intestine (the ileum) and the beginning of the large intestines, the ascending colon or cecum...”
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More topics Related to Small Intestine


...related topic
“...The surgeon makes an opening in the abdomen and attaches the bottom of the small intestine (ileum) to it.”


...related topic
“The lower two-thirds of the small intestine, ending in the ileocecal valve and emptying into the cecum of the colon...”

Increased Intestinal Permeability / Leaky Gut

...the condition
“...The junctions between cells not only need to be 'tight' but the surface area of the small intestine must be large for normal nutrient processing to occur...”

Intestinal Malabsorption Syndrome

...the condition
“Alternative names: Impaired Intestinal Absorption This condition is a state of impaired absorption of nutrients in the small intestine.  Specific causes – of which there are many – lead to different patterns in malabsorption, involving for example fat and fat-soluble vitamins (A, D, E and K), vitamin B12, folic acid...”

Intestinal Obstruction

...the condition
“...Most of the 6-8 liters of fluid that enter the small bowel each day is absorbed through the microvilli in the small intestine...”

Intoxication Susceptibility

...recommendation Increased Calorie Consumption
“...When food and alcohol are consumed at the same time this prevents the alcohol from passing quickly into the small intestine from where it would be rapidly absorbed giving the enzyme more time to work.”

Intrinsic Factor

...related topic
“...proteins secreted from the lining of the stomach whose sole purpose is (it seems) to cradle B12 and carry it through the digestive system until it reaches the absorption sites in the last foot of small intestine.  There it slips from one protein to the other, and into the cell membranes where its handed over to the specialized blood protein that can carry it safely to the final target tissues...”

Iron a treatment
“...The absorption of iron takes place in the duodenum and upper jejunum (small intestine).  Of total iron intake, only 5-15% is absorbed...”


...related topic
“The lower end of the small intestine.”

Left Hypochondriac

...related topic
“...It contains the spleen, left kidney, pancreas, stomach, liver tip, pancreas tail, descending colon, transverse colon, and small intestine.”

Lipase a treatment
“...Lipase is the enzyme required to break down fats and lipids (to give mono- and diglycerides, glycerol and free fatty acids) and is produced in the pancreas before being released into the small intestine.  Digesting fats and lipids is difficult because they have to be carried by a water-based transport system – the blood and lymph...”

Liver Detoxification / Support Requirement

...recommendation Coffee Enema
“The coffee enema causes the liver to produce more bile (which contains processed toxins) and moves bile out towards the small intestine for elimination...”

Magnesium Requirement

...the condition
“...Magnesium is absorbed toward the end of the small intestine.  If any portion of this area (called the ileum) has been removed, magnesium absorption will be reduced...”


...the condition
“...Systemic mastocytosis is caused by mast cells accumulating in the tissues and can affect organs such as the liver, spleen, bone marrow, and small intestine.  When too many mast cells are present in the body, the chemicals that they release can cause...”

Mesenteric Ischemia

...the condition
“...There are four ways in which poor blood flow to the small intestine can occur: a moving blood clot becoming lodged in an artery; a new blood clot forming in an artery; a blood clot forming in the mesenteric vein; and insufficient blood flow due to low...”

Ozone / Oxidative Therapy a treatment
“...there have been reports of improved health with oral use, physicians like Dr. Farr believed that taking hydrogen peroxide orally could have a corrosive and tumorous effect on the stomach and small intestine and advised against using it...”


...the condition
“...The enzymes travel to the small intestine, where they break down protein, fats and other nutrients...”

Parasite Infection

...relationship to Bacterial Dysbiosis
Small bowel parasites may predispose a person to bacterial overgrowth in the small intestine.”

Peyer's Patches

...related topic
“Lymphoid follicles similar to lymph nodes or the tonsils, located especially in the lower small intestine.  They contain white blood cells, defend against invading bacteria and try to prevent inadequately digested food particles from crossing the gut wall and entering the blood...”

Pinworm Infection

...the condition
“...Pinworm eggs are swallowed and hatch in the small intestine.  They then move on to the large intestine where they find a warm, dark place to attach and live...”

Poor Small Intestine Health

...the condition
“The small intestine is involved in the digestion, absorption and transport of food...”
...recommendation Slippery Elm
“Slippery elm tea is reported to be beneficial against inflammation of the small intestine.”
...recommendation Lactobacillus Acidophilus
“...It colonizes the walls of the small intestine, secretes substances that help maintain a balance of intestinal microflora (by creating a favorable environment for the growth of beneficial flora), and helps keep the intestinal wall...”

Rapid Intestinal Transit

...the condition
“...A 50% emptying of the small intestine then takes another 2½ to 3 hours, and the final stage – transit through the colon – normally takes 16-40 hours...”

Rapid Stomach Emptying (Gastric Dumping)

...the condition
“...Rapid gastric emptying happens when the lower end of the small intestine (jejunum) fills too quickly with undigested food from the stomach...”

Raw Food Diet a treatment
“...also suggest that perhaps other differences between our digestive systems and those of the great apes may also have been because of our adaptation to cooked foods – our smaller gut volume, longer small intestine, smaller colon, and faster gut passage rate...”

Right Hypochondriac

...related topic
“...It contains the liver, gallbladder, right kidney, small intestine, transverse colon, and ascending colon.”

Roundworm Infection

...the condition
“...Adult worms can live in the small intestine for 6 months or longer...”

Short Bowel Syndrome

...the condition
“...Short bowel syndrome is a malabsorption disorder in which part(s) of the small intestine are missing either due to surgery, a congenital defect, or dysfunction of a large segment of bowel...”
...our question about Removal of section of small bowel
“If surgery leaves less than 200cm (about 7 feet) of viable small bowel, the risk for developing short-bowel syndrome is high.”

Small Bowel Resection

...related topic
“A surgical procedure to remove part or all of the small bowel (small intestine) that is blocked or diseased.”

Small Intestine Cancer

...the condition
“A rare condition in which cancerous tumors develop in the small bowel.  The most common types include adenocarcinoma, lymphoma, sarcoma, and carcinoids...”

Sphincter of Oddi Dysfunction

...the condition
“...When this valve loses its ability to contract and relax during a meal, the flow of digestive juices (bile and pancreatic juice) into the small intestine is obstructed, leading to severe abdominal pain and other possible complications...”


...the condition
“...The underlying condition causes of steatorrhea include ... Malabsorption of fats in small intestine...”
...related topic
“...This may be the result of failing to inoculate fatty foods with enough surfactant (biliary soap) to digest them, the failure of the lower small intestine to absorb them, or simply too much fat for even normal digestion to handle...”
...our question about Undigested fat in stools
“...When secretions from the pancreas and liver are adequate, emulsified dietary fats are almost completely absorbed in the small intestine.  When a malabsorption disorder or another cause disrupts this process, excretion of fat in the stool increases.”

Strongyloides stercoralis Infection

...the condition
“...Parasitic females anchor themselves with their mouths to the mucosa of the small intestine or burrow their anterior ends into the submucosa...”

Supplemental Fiber a treatment
“...Fiber in food often is released more slowly into the small intestine, and while beneficial, works less effectively in removing large amounts of bile and its constituents...”

Tapeworm Infection

...the condition
“...The worms attach high up in the small intestine and grow downwards...”

Tendency To Develop Polyps

...the condition
“...Polyps are typically associated with mucous membranes and can occur in various parts of the body, including the colon, nose, sinuses, stomach, bladder, uterus, cervix and small intestine.  Polyps of the colon and rectum grow from the lining of the colon...”


...the condition
“...They then pass into the small intestine where they develop into mature males and females in about 2 days...”

Trypsin a treatment
“...Trypsin continues the process of digestion (which began in the stomach) in the small intestine where a slightly alkaline environment (about pH 8) promotes its maximal enzymatic activity.”

Typhoid Fever

...the condition
“...Germs enter the body through the mouth, causing irritation and ulceration of the lower small bowel.  The condition is common in tropical countries with poor sanitation...”

Urinary Retention

...the condition
“...Bladder Stones; Bladder Cancer; Fecal Impaction; Gastrointestinal Cancer: Biliary, Pancreatic, Small Bowel, Colon, Rectal, Anal; Retroperitoneal Tumor (very rare); Foreign body in the urethra; Urethral stones (stones that have become stuck after leaving the bladder); Schistosomiasis (parasitic...”


...related topic
“The villi are small but significant structures of the mucosal layer of the small intestine.  They are finger-like (or hair-like) projections, 0.5 to 1mm in length, that cover the mucosal surface and increase its absorptive area...”

Vitamin B12 Requirement

...the condition
“...The secreted intrinsic factor then binds to B12 and this complex (IF-B12) travels to the end of the small intestine where it crosses the intestinal wall into the bloodstream...”

Vitamin B2 (Riboflavin) a treatment
“...Vitamin B2 is easily absorbed from the small intestine into the blood which transports it to the tissues...”

Vitamin B3 (Niacin) a treatment
“...A white crystalline substance that is soluble in both water and alcohol, niacin and niacinamide are both readily absorbed from the small intestine.  Small amounts may be stored in the liver, but most of the excess is excreted in the urine...”

Weakened Immune System

...relationship to Small Intestine Cancer
“Lymphoma of the small intestine is strongly associated with a weakened immune system such as occurs with AIDS.”

Weight Loss a treatment
“...Combined restrictive and malabsorptive surgery is a combination of restrictive surgery as described above, along with bypass or malabsorptive surgery, in which the stomach is connected to the small intestine, bypassing the duodenum, which is the beginning portion of the small intestine...”

Weight Loss Surgery a treatment
“...Weight loss surgery works by restricting the amount of food the stomach can hold, and by decreasing the absorption of food in the stomach and small intestine.  The two most common types of weight loss surgery are gastric banding and gastric bypass surgery...”

Whipworm Infection

...the condition
“...Once in the intestine, the eggs hatch into larvae, which grow and develop in the small intestine before moving to another part of the intestines – the cecum...”

Wilson's Disease

...the condition
“...The small intestine absorbs too much copper and the liver excretes too little of it, resulting in a copper buildup in the liver and brain...”
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