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...”
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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...”
...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...”


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


...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...”

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...”


...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...”


...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...”


...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...”

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...”

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 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...”
...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 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...”
...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 2/5 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
“...{Figure 1}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...”


...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...”
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More topics Related to Small Intestine

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...”

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...”

Iron a treatment
“...The absorption of iron takes place in the duodenum and upper jejunum (small intestine)...”


...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...”

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...”


...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...”

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
“...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...”

Pinworm Infection

...the condition
“...Causes and Development: Pinworm eggs are swallowed and hatch in the small intestine...”

Poor Small Intestine Health

...the condition
“The small intestine is involved in the digestion, absorption and transport of food...”
...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...”
...recommendation Slippery Elm
“Slippery elm tea is reported to be beneficial against inflammation of the small intestine...”

Rapid Intestinal Transit

...the condition
“...A 50% emptying of the small intestine then takes another 2...”

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...”

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...”

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...”


...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...”

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...”

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
“...Source: 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...”

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...”

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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