Low-FODMAP dietdiet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyolslow-FODMAP diets
FODMAPs are not the cause of irritable bowel syndrome nor other functional gastrointestinal disorders, but rather a person develops symptoms when the underlying bowel response is exaggerated or abnormal. Fructose malabsorption and lactose intolerance may produce IBS symptoms through the same mechanism but, unlike with other FODMAPs, poor absorption of fructose is found in only a minority and, in certain populations, notably those of European descent, lactose intolerance is found in only a minority. Many who benefit from a low FODMAP diet need not restrict fructose or lactose.


diarrhoeadiarrheal diseaseschronic diarrhea
These include lactose intolerance, irritable bowel syndrome, non-celiac gluten sensitivity, celiac disease, inflammatory bowel disease, hyperthyroidism, bile acid diarrhea, and a number of medications. In most cases, stool cultures to confirm the exact cause are not required. Diarrhea can be prevented by improved sanitation, clean drinking water, and hand washing with soap. Breastfeeding for at least six months and vaccination against rotavirus is also recommended. Oral rehydration solution (ORS)--clean water with modest amounts of salts and sugar—is the treatment of choice. Zinc tablets are also recommended.

Gluten-free diet

gluten-freegluten freegluten free diet
Following a lifelong gluten-free diet is the only medically-accepted treatment for people with coeliac disease. Non-coeliac gluten sensitivity (NCGS) is described as a condition of multiple symptoms that improves when switching to a gluten-free diet, after coeliac disease and wheat allergy are excluded. People with NCGS may develop gastrointestinal symptoms, which resemble those of irritable bowel syndrome (IBS) or a variety of nongastrointestinal symptoms. Gastrointestinal symptoms may include any of the following: abdominal pain, bloating, bowel habit abnormalities (either diarrhoea or constipation), nausea, aerophagia, gastroesophageal reflux disease, and aphthous stomatitis.

Food intolerance

intolerancefood sensitivityFood Intolerances
Fructose malabsorption. Gluten sensitivity. Gluten-sensitive enteropathy. Fructose intolerance. Histamine intolerance, also related to biogenic amines intolerance / BAI. Lactose intolerance. Orthorexia. Salicylate sensitivity. Sodium phosphates. Sucrose intolerance.

Crohn's disease

Crohn’s diseasechronCrohn
Mouse studies have suggested some symptoms of Crohn's disease, ulcerative colitis, and irritable bowel syndrome have the same underlying cause. Biopsy samples taken from the colons of all three patient groups were found to produce elevated levels of a serine protease. Experimental introduction of the serine protease into mice has been found to produce widespread pain associated with irritable bowel syndrome, as well as colitis, which is associated with all three diseases. Regional and temporal variations in those illnesses follow those associated with infection with the protozoan Blastocystis.

Small intestine

small bowelsmall intestinessmall
Crohn's disease, and the more general inflammatory bowel disease. Typhlitis (neutropenic colitis in the immunosuppressed. Coeliac disease (sprue or non-tropical sprue). Mesenteric ischemia. Embolus or thrombus of the superior mesenteric artery or the superior mesenteric vein. Arteriovenous malformation. Gastric dumping syndrome. Irritable bowel syndrome. Duodenal (peptic) ulcers. Gastrointestinal perforation. Hyperthyroidism. Diverticulitis. Radiation enterocolitis. Mesenteric cysts. Peritoneal Infection. Sclerosing retroperitonitis. Small intestinal bacterial overgrowth. Endometriosis. Large intestine. Stomach.


bloatedabdominal bloatinggas
Lactose intolerance, fructose intolerance and other food intolerances. Premenstrual Syndrome. Food allergy. Aerophagia (air swallowing, a nervous habit). Irritable bowel syndrome. Celiac disease. Non-celiac gluten sensitivity. Partial bowel obstruction. Gastric dumping syndrome or rapid gastric emptying. Gas-producing foods. Constipation. Visceral fat. Splenic-flexure syndrome. Menstruation, dysmenorrhea. Polycystic ovary syndrome and ovarian cysts. Alvarez' syndrome, bloating of unknown or psychogenic origin without excess of gas in the digestive tract. Massive infestation with intestinal parasites (e.g., Ascaris lumbricoides). Diverticulosis. Certain medications, such as phentermine.


malabsorption syndromeintestinal malabsorptionmalabsorption of nutrients
Gluten-free diet in coeliac disease. Lactose avoidance in lactose intolerance. Antibiotic therapy to treat Small Bowel Bacterial overgrowth. Cholestyramine or other bile acid sequestrants will help reducing diarrhoea in bile acid malabsorption. Fructose malabsorption. Protein losing enteropathy.


nauseousvomitingfeeling of sickness
Small bowel obstruction. Colonic obstruction. Superior mesenteric artery syndrome. Viral infection. Bacterial infection. Celiac disease. Cholecystitis. Pancreatitis. Appendicitis. Hepatitis. Gastroparesis. Intestinal pseudo-obstruction. Gastroesophageal reflux disease. Irritable bowel syndrome. Chronic idiopathic nausea. Functional vomiting. Cyclic vomiting syndrome. Non-celiac gluten sensitivity. Biliary colic. Abdominal irradiation. Cardiomyopathy. Myocardial infarction (heart attack). Motion sickness. Labyrinthitis. Malignancy. Malignancy. Hemorrhage. Abscess. Hydrocephalus. Meningitis. Encephalitis. Anorexia and bulimia nervosa. Depression. Chemotherapy. Antibiotics. Antiarrhythmics.

Inflammatory bowel disease

inflammatory bowel diseasesIBDindeterminate colitis
Other diseases may cause an increased excretion of fecal calprotectin, such as infectious diarrhea, untreated coeliac disease, necrotizing enterocolitis, intestinal cystic fibrosis and neoplastic pediatric tumor cells. Conditions with similar symptoms as Crohn's disease includes intestinal tuberculosis, Behçet's disease, ulcerative colitis, nonsteroidal anti-inflammatory drug enteropathy, irritable bowel syndrome and coeliac disease. Conditions with similar symptoms as ulcerative colitis includes acute self-limiting colitis, amebic colitis, schistosomiasis, Crohn's disease, colon cancer, irritable bowel syndrome, intestinal tuberculosis and nonsteroidal anti-inflammatory drug enteropathy.


stomach flucholera morbusinfectious diarrhea
Other potential causes of signs and symptoms that mimic those seen in gastroenteritis that need to be ruled out include appendicitis, volvulus, inflammatory bowel disease, urinary tract infections, and diabetes mellitus. Pancreatic insufficiency, short bowel syndrome, Whipple's disease, coeliac disease, and laxative abuse should also be considered. The differential diagnosis can be complicated somewhat if the person exhibits only vomiting or diarrhea (rather than both). Appendicitis may present with vomiting, abdominal pain, and a small amount of diarrhea in up to 33% of cases. This is in contrast to the large amount of diarrhea that is typical of gastroenteritis.

Gluten-related disorders

gluten intolerancegluten-sensitive enteropathygluten sensitivity
Non-celiac gluten sensitivity (NCGS), or gluten sensitivity (GS), is a syndrome in which patients develop a variety of intestinal and/or extraintestinal symptoms that improve when gluten is removed from the diet, after coeliac disease and wheat allergy are excluded. NCGS, which is possibly immune-mediated, now appears to be more common than coeliac disease, with a prevalence estimated to be 6–10 times higher. Gastrointestinal symptoms, which resemble those of irritable bowel syndrome (IBS), may include any of the following: abdominal pain, bloating, bowel habit abnormalities (either diarrhea or constipation), nausea, aerophagia, gastroesophageal reflux disease, and aphthous stomatitis.

Wheat allergy

Wheatallergic to wheatbaker's asthma
While gluten is also the causative agent of celiac disease (CD), celiac disease can be contrasted to gluten allergy by the involvement of different immune cells and antibody types (See Comparative pathophysiology of gluten sensitivities), and because the list of allergens extend beyond the classic gluten category of proteins. Prolamins and the closely related glutelins, a recent study in Japan found that glutenins are a more frequent allergen, however gliadins are associated with the most severe disease. A proteomics based study found a γ-gliadin isoform gene. Glutenin (wheat glutelin) is a predominant allergen in wheat.


Some gastroenterology trainees will complete a "fourth-year" (although this is often their seventh year of graduate medical education) in transplant hepatology, advanced endoscopy, inflammatory bowel disease, motility or other topics. Hepatology, or hepatobiliary medicine, encompasses the study of the liver, pancreas, and biliary tree, while proctology encompasses the fields of anus and rectum diseases. They are traditionally considered sub-specialties of gastroenterology. Citing from Egyptian papyri, John F. Nunn identified significant knowledge of gastrointestinal diseases among practicing physicians during the periods of the pharaohs.

Gastrointestinal tract

intestinegastrointestinaldigestive tract
Different types of surgery and treatment managing life-threatening complications such as ileus and volvulus, intestinal stasis which lead to bacterial overgrowth, and resection of affected or dead parts of the gut may be needed. Many patients require parenteral nutrition. Ileus is a blockage of the intestines. Coeliac disease is a common form of malabsorption, affecting up to 1% of people of northern European descent. An autoimmune response is triggered in intestinal cells by digestion of gluten proteins. Ingestion of proteins found in wheat, barley and rye, causes villous atrophy in the small intestine.


allergiesallergicallergic reaction
Symptoms of food allergy include abdominal pain, bloating, vomiting, diarrhea, itchy skin, and swelling of the skin during hives. Food allergies rarely cause respiratory (asthmatic) reactions, or rhinitis. Insect stings, food, antibiotics, and certain medicines may produce a systemic allergic response that is also called anaphylaxis; multiple organ systems can be affected, including the digestive system, the respiratory system, and the circulatory system. Depending on the rate of severity, anaphylaxis can include skin reactions, bronchoconstriction, swelling, low blood pressure, coma, and death. This type of reaction can be triggered suddenly, or the onset can be delayed.


constipatedobstipationchronic constipation
Celiac disease and non-celiac gluten sensitivity may also present with constipation. Cystocele can develop as a result of chronic constipation. Constipation can be caused or exacerbated by a low-fiber diet, low liquid intake, or dieting. Dietary fiber helps to decrease colonic transport time, increases stool bulk but simultaneously softens stool. Therefore, diets low in fiber can lead to primary constipation. Many medications have constipation as a side effect.

Diabetes mellitus type 1

type 1 diabetesjuvenile diabetestype 1
The signs and symptoms of diabetic ketoacidosis include dry skin, rapid deep breathing, drowsiness, increased thirst, frequent urination, abdominal pain, and vomiting. About 12 percent of people with type 1 diabetes have clinical depression. About 6 percent of people with type 1 diabetes have celiac disease, but in most cases there are no digestive symptoms or are mistakenly attributed to poor control of diabetes, gastroparesis or diabetic neuropathy. In most cases, celiac disease is diagnosed after onset of type 1 diabetes. The association of celiac disease with type 1 diabetes increases the risk of complications, such as retinopathy and mortality.


exhaustionOverexertionfeeling tired
Autoimmune diseases such as celiac disease, lupus, multiple sclerosis, myasthenia gravis, Sjögren's syndrome, and spondyloarthropathy. Blood disorders such as anemia and hemochromatosis. Cancer, in which case it is called cancer fatigue. Chronic fatigue syndrome (CFS). Drug abuse including alcohol abuse. Depression and other mental disorders that feature depressed mood. Developmental disorders such as autism spectrum disorder. Eating disorders, which can produce fatigue due to inadequate nutrition. Endocrine diseases like diabetes mellitus and hypothyroidism. Fibromyalgia. Gulf War syndrome. Heart disease. HIV. Inborn errors of metabolism such as fructose malabsorption.

Abdominal distension

abdominal distentiondistensiondistended
Celiac disease. Coccidiosis. Cystic fibrosis. Diverticulitis. Eosinophilic gastroenteritis. Fasciolosis. Gastroparesis. Giardiasis. Hookworm disease. Inflammatory bowel disease (Crohn's disease and ulcerative colitis). Kidney stones. Kwashiorkor. Lactose intolerance. Obstructed bowel. Ovarian cancer. Polycystic liver disease. Pregnancy. Premenstrual syndrome. Pseudomonas aeruginosa infection. Small bowel bacterial overgrowth syndrome. Strongyloidiasis. Tropical sprue. Weight gain. Whipple's disease. Constipation. Lactose intolerance and other food intolerances. Overeating (due to overproduction of gases in the digestion process ). Celiac disease. GERD (gastroesophageal reflux disease).


schizophrenicschizophrenicspositive symptoms
It has been hypothesized that in some people, development of schizophrenia is related to intestinal tract dysfunction such as seen with non-celiac gluten sensitivity or abnormalities in the intestinal flora. A subgroup of persons with schizophrenia present an immune response to gluten different from that found in people with celiac, with elevated levels of certain serum biomarkers of gluten sensitivity such as anti-gliadin IgG or anti-gliadin IgA antibodies. About half of those with schizophrenia use drugs or alcohol excessively.


duodenaldodecadactylumduodenal cap
Duodenal ulcers may cause recurrent abdominal pain and dyspepsia, and are often investigated using a urea breath test to test for the bacteria, and endoscopy to confirm ulceration and take a biopsy. If managed, these are often managed through antibiotics that aim to eradicate the bacteria, and PPIs and antacids to reduce the gastric acidity. The British Society of Gastroenterology (BSG) guidelines specify that a duodenal biopsy is required for the diagnosis of adult celiac disease. The biopsy is ideally performed at a moment when the patient is on a gluten-containing diet. Other causes of disease include: * Pancreas * Duodenum at the Human Protein Atlas Anterior. Gallbladder.

Food allergy

food allergiesfood allergensallergy
Lactose intolerance generally develops later in life, but can present in young patients in severe cases. It is due to an enzyme deficiency (lactase) and not allergy, and occurs in many non-Western people. Celiac disease. While it is caused by a permanent intolerance to gluten (present in wheat, rye, barley and oats), is not an allergy nor simply an intolerance, but a chronic, multiple-organ autoimmune disorder primarily affecting the small intestine. Irritable bowel syndrome. C1 Esterase inhibitor deficiency (hereditary angioedema), a rare disease, generally causes attacks of angioedema, but can present solely with abdominal pain and occasional diarrhea.


Celiac disease. Non-celiac gluten sensitivity. Pyloric stenosis (in babies, this typically causes a very forceful "projectile vomiting" and is an indication for urgent surgery). Bowel obstruction. Overeating. Acute abdomen and/or peritonitis. Ileus. Food allergies (often in conjunction with hives or swelling). Cholecystitis, pancreatitis, appendicitis, hepatitis. Food poisoning. In children, it can be caused by an allergic reaction to cow's milk proteins (Milk allergy or lactose intolerance). Movement: motion sickness (which is caused by overstimulation of the labyrinthine canals of the ear). Ménière's disease. Concussion. Cerebral hemorrhage. Migraine.


Triticeae glutens. Immunochemistry of gluten. Anti-gliadin antibodies. Gluten immunochemistry. Glutenin. Non-celiac gluten sensitivity. Gluten-related disorders. Intestinal permeability.