The main symptoms of AIE include:

- Diarrhea (frequent loss of fluids)

- Intestinal inflammation

- Vomiting

- Intestinal bleeding

- Difficulty or inability to gain weight

- Rapid weight loss

- Decreased urine output from dehydration

Congenital tufting enteropathy is an inherited disorder of the small intestine that presents with intractable diarrhea in young children.

It is characterized by chronic, intractable diarrhea in new-born infants, starting in the first few days of life.

This results in metabolic acidosis and severe dehydration. Pregnancy and birth are usually normal.

Microvillus inclusion disease, also known as Davidson's disease, congenital microvillus atrophy and, less specifically, microvillus atrophy (note: microvillus is often misspelled as microvillous), is a rare genetic disorder of the small intestine that is inherited in an autosomal recessive pattern.

Tricho-hepato-enteric syndrome is one particular form of intractable diarrhea of infancy, presenting typically in the first month of life. These babies were usually born small for their age and continue to experience failure to thrive, usually with a final short stature. Typical facial features include prominent forehead and cheeks, a broad nasal root and widely spaced eyes (hypertelorism). Their hairs are woolly, easily removed and poorly pigmented. Liver disease is mainly present as cirrhosis or fibrosis, and staining might reveal high iron content of the liver cells (consistent with hemochromatosis). Most evaluated patients had some degree of decrease in intelligence.

The first cases appears to have been reported in 1978 by Davidson et al. These authors reported a five cases of intractable diarrhoea four of whom died. Post mortum showed a thin and dilated intestine with flat small bowel mucosa. A number of jejunal biopsies had been taken during life and these showed partial villous atrophy with by crypt hyperplasia and an increased number of mitotic figures in the crypts. Normal numbers and types of mononuclear cells were present in the lamina propria. Most notably focal epithelial tufts were found on the surface epithelium. These tufts were composed of closely packed enterocytes with apical rounding of the plasma membrane, resulting in a teardrop configuration of the cells. Inclusion bodies or secretory granules were not visualised on transmission electron microscopy within the cytoplasm of the villous enterocytes.

Reifen "et al" reported 2 additional cases in 1994 and coined the name congenital tufting enteropathy.

Autoimmune enteropathy (AIE) is a rare disorder of the immune system condition that affects infants, young children and (rarely) adults causing severe diarrhea, vomiting, and other morbidities of the digestive tract. AIE causes malabsorption of food, vitamins, and minerals often necessitating replacement fluids and total parenteral nutrition. Some disorders, such as IPEX Syndrome, include autoimmune enteropathy as well as autoimmune "pathies" of the skin, thyroid, other glands, or kidneys.

EE is rarely symptomatic and is considered a subclinical condition. However, adults may have mild symptoms or malabsorption such as altered stool consistency, increased stool frequency and weight loss.

Tricho-hepato-enteric syndrome (THE), also known as syndromic or phenotypic diarrhea, is an extremely rare congenital bowel disorder which manifests itself as intractable diarrhea in infants with intrauterine growth retardation, hair and facial abnormalities. Many also have liver disease and abnormalities of the immune system. The associated malabsorption leads to malnutrition and failure to thrive.

It is thought to be a genetic disorder with an autosomal recessive inheritance pattern, although responsible genes have not been found and the exact cause remains unknown. Prognosis is poor; many patients die before the age of 5 (mainly from infections or cirrhosis), although most patients nowadays survive with intravenous feeding (parenteral nutrition).

Environmental enteropathy is believed to result in chronic malnutrition and subsequent growth stunting (low height-for-age measurement) as well as other child development deficits.

This condition causes severe infections. it is characterized by elevated immunoglobulins that function poorly.

Other symptoms are:

- Bronchiectasis

- Hepatosplenomegaly

- Pyoderma

- Emphysema

- Diarrhea

CCD causes persistent secretory diarrhea. In a fetus, it leads to polyhydramnios and premature birth. Immediately after birth, it leads to dehydration, hypoelectrolytemia, hyperbilirubinemia, abdominal distention, and failure to thrive.

Protein losing enteropathy refers to any condition of the gastrointestinal tract (e.g. damage to the gut wall) that results in a net loss of protein from the body.

Some of the symptoms and signs of IPEX syndrome are the following:

Signs and symptoms of the disease include diarrhea, nausea, swelling of the legs, protein-losing enteropathy, immunodeficiency and loss of lymphatic fluid into the intestines. It is usually diagnosed before the patient is 3 years old, but it is sometimes diagnosed in adults.

LRBA deficiency presents as a syndrome of autoimmunity, lymphoproliferation, and humoral immune deficiency. Predominant clinical problems include idiopathic thrombocytopenic purpura (ITP), autoimmune hemolytic anemia (AIHA), and an autoimmune enteropathy. Before the discovery of these gene mutations, patients were diagnosed with common variable immune deficiency (CVID), which is characterized by low antibody levels and recurrent infections. Infections mostly affect the respiratory tract, as many patients suffer from chronic lung disease, pneumonias, and bronchiectasis. Lymphocytic interstitial lung disease (ILD) is also observed, which complicates breathing and leads to impairment of lung function and mortality. Infections can also occur at other sites, such as the eyes, skin and gastrointestinal tract. Many patients suffer from chronic diarrhea and inflammatory bowel disease. Other clinical features can include hepatosplenomegaly, reoccurring warts, growth retardation, allergic dermatitis, and arthritis. Notably, LRBA deficiency has also been associated with type 1 diabetes mellitus. There is significant clinical phenotypic overlap with disease caused by CTLA4 haploinsufficiency. Since LRBA loss results in a loss of CTLA4 protein, the immune dysregulation syndrome of LRBA deficient patients can be attributed to the secondary loss of CTLA4. Because the predominant features of the disease include autoantibody-mediated disease (AIHA, ITP), Treg defects (resembling those found in CTLA4 haploinsufficient patients), autoimmune infiltration (of non-lymphoid organs, also resembling that found in CTLA4 haploinsufficient patients), and enteropathy, the disease has been termed LATAIE for LRBA deficiency with autoantibodies, Treg defects, autoimmune infiltration, and enteropathy.

The signs/symptoms of protein losing enteropathy are consistent with diarrhea, fever, and general abdominal discomfort. Swelling of the legs due to peripheral edema can also occur, however if the PLE is related to a systemic disease such as congestive heart failure or constrictive pericarditis, then the symptoms could be of the primary disease development.

Enteropathy refers to any pathology of the intestine. Although enteritis specifically refers to an inflammation of the intestine, and is thus a more specific term than "enteropathy", the two phrases are sometimes used interchangeably.

EG typically presents with a combination of chronic nonspecific GI symptoms which include abdominal pain, diarrhea, occasional nausea and vomiting, weight loss and abdominal distension. Approximately 80% have symptoms for several years; a high degree of clinical suspicion is often required to establish the diagnosis, as the disease is extremely rare. It doesn't come all of a sudden but takes about 3–4 years to develop depending upon the age of the patient. Occasionally, the disease may manifest itself as an acute abdomen or bowel obstruction.

- Mucosal EG (25–100%) is the most common variety, which presents with features of malabsorption and protein losing enteropathy. Failure to thrive and anaemia may also be present. Lower gastrointestinal bleeding may imply colonic involvement.

- Muscular EG (13–70%) present with obstruction of gastric outlet or small intestine; sometimes as an obstructing caecal mass or intussusception.

- Subserosal EG (4.5% to 9% in Japan and 13% in the US) presents with ascites which is usually exudative in nature, abundant peripheral eosinophilia, and has favourable responses to corticosteroids.

- Other documented features are cholangitis, pancreatitis, eosinophilic splenitis, acute appendicitis and giant refractory duodenal ulcer.

IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked) syndrome is a rare disease linked to the dysfunction of the transcription factor FOXP3, widely considered to be the master regulator of the regulatory T cell lineage. It leads to the dysfunction of regulatory T-cells and the subsequent autoimmunity. The disorder manifests with autoimmune enteropathy, psoriasiform or eczematous dermatitis, nail dystrophy, autoimmune endocrinopathies, and autoimmune skin conditions such as alopecia universalis and bullous pemphigoid.

Management for immunodysregulation polyendocrinopathy enteropathy X-linked syndrome has seen limited success in treating the syndrome by bone marrow transplantation.

Polyps are most frequent in the stomach and large intestine, are also found in the small intestine, and are least frequent in the esophagus. A biopsy will reveal them to be hamartomas; the possibility that they progress to cancer is generally considered to be low, although it has been reported multiple times in the past. Chronic diarrhea and protein-losing enteropathy are often observed. Possible collateral features include variable anomalies of ectodermal tissues, such as alopecia, atrophy of the nails, or skin pigmentation

Individuals with acrodermatitis enteropathica may present with the following:

- Blistering of skin

- Dry skin

- Emotional lability

- Glossitis

- Pustule

Alopecia (loss of hair from the scalp, eyebrows, and eyelashes) may occur. Skin lesions may be secondarily infected by bacteria such as "Staphylococcus aureus" or fungi such as "Candida albicans". These skin lesions are accompanied by diarrhea.

The illness is usually caused by lymphatic vessels that were misshaped at birth, causing obstruction and subsequent enlargement. The condition can also be a result of other illnesses such as constrictive pericarditis and pancreatitis. The disease is diagnosed by doing a biopsy of the affected area. Severity of the disease is then determined by measuring alpha-antitrypsin proteins in a stool sample.

LRBA deficiency is a rare genetic disorder of the immune system. This disorder is caused by a mutation in the gene "LRBA". LRBA stands for “Lipopolysaccharide (LPS)-responsive vesicle trafficking, beach- and anchor-containing” gene. This condition is characterized by autoimmunity, lymphoproliferation, and immune deficiency. It was first described by Gabriela Lopez-Herrera from University College London in 2012. Investigators in the laboratory of Dr. Michael Lenardo at National Institute of Allergy and Infectious Diseases, the National Institutes of Health and Dr. Michael Jordan at Cincinnati Children’s Hospital Medical Center later described this condition and therapy in 2015.

Ten (of 75) young patients had neurologic findings such as febrile seizures, single generalized seizures, mild ataxia, and muscular hypotonia with retarded motor development, but magnetic resonance imaging detected unilateral and bilateral T2-hyperintensive white-matter lesions in 15 patients (20%)