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.

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.

Fibrosing colonopathy is a disease that arises in patients with cystic fibrosis treated with enteric coated pancreatic enzyme supplements. The disease is associated with high dose of these supplements. The clinical presentation of fibrosing colonopathy is non-specific. Abdominal pain, distension, vomiting, and constipation are frequent

features and have led initially to confusion with distal intestinal obstruction syndrome. In some instances, the clinical and radiological features were suggestive of Crohn's disease or inflammatory colitis.

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.

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).

The primary symptoms of IBS are abdominal pain or discomfort in association with frequent diarrhea or constipation and a change in bowel habits. Symptoms usually are experienced as acute attacks that subside within one day, but recurrent attacks are likely. There may also be urgency for bowel movements, a feeling of incomplete evacuation (tenesmus), bloating, or abdominal distension. In some cases, the symptoms are relieved by bowel movements. People with IBS, more commonly than others, have gastroesophageal reflux, symptoms relating to the genitourinary system, chronic fatigue syndrome, fibromyalgia, headache, backache, and psychiatric symptoms such as depression and anxiety. About a third of men and women who have IBS also report sexual dysfunction typically in the form of a reduction in libido.

IBS can be classified as either diarrhea-predominant (IBS-D), constipation-predominant (IBS-C), or with alternating stool pattern (IBS-A) or pain-predominant. In some individuals, IBS may have an acute onset and develop after an infectious illness characterized by two or more of: fever, vomiting, diarrhea, or positive stool culture. This postinfective syndrome has consequently been termed "postinfectious IBS" (IBS-PI).

Usually the patient has abdominal distention, pain and altered bowel movements. There may also be nausea and vomiting.

Ogilvie syndrome is the acute dilation of the colon in the absence of any mechanical obstruction in severely ill patients.

Colonic pseudo-obstruction is characterized by massive dilatation of the cecum (diameter > 10 cm) and right colon on abdominal X-ray. It is a type of megacolon, sometimes referred to as "acute megacolon", to distinguish it from toxic megacolon.

The condition carries the name of the British surgeon Sir (1887–1971), who first reported it in 1948.

Signs and symptoms of typhlitis may include diarrhea, a distended abdomen, fever, chills, nausea, vomiting, and abdominal pain or tenderness.

In spite of Crohn's and UC being very different diseases, both may present with any of the following symptoms: abdominal pain, vomiting, diarrhea, rectal bleeding, severe internal cramps/muscle spasms in the region of the pelvis and weight loss. Anemia is the most prevalent extraintestinal complication of inflammatory bowel disease. Associated complaints or diseases include arthritis, pyoderma gangrenosum, primary sclerosing cholangitis, and non-thyroidal illness syndrome (NTIS). Associations with deep vein thrombosis (DVT) and bronchiolitis obliterans organizing pneumonia (BOOP) have also been reported. Diagnosis is generally by assessment of inflammatory markers in stool followed by colonoscopy with biopsy of pathological lesions.

Neutropenic enterocolitis, also known as typhlitis or typhlenteritis, and less commonly called caecitis or cecitis, is inflammation of the cecum (part of the large intestine) that may be associated with infection. It is particularly associated with neutropenia, a low level of neutrophil granulocytes (the most common form of white blood cells) in the blood.

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine. Crohn's disease and ulcerative colitis are the principal types of inflammatory bowel disease. It is important to note that not only does Crohn's disease affect the small intestine and large intestine, it can also affect the mouth, esophagus, stomach and the anus whereas ulcerative colitis primarily affects the colon and the rectum.

The main symptom of enteric neuropathy is severe and constant pain. Other symptoms include nausea, vomiting, diarrhoea, constipation, bloating and abdominal abnormalities. In addition malabsorption and poor nutrition are common, as the digestive system begins to fail. Symptom management is very important and the main priority is usually to get on top of the pain. However, as most people may have been waiting for years for a diagnosis they are often already addicted to painkillers (such as tramadol and oramorph) and these have adverse effects on the primary condition.

The diagnosis of enteric neuropathy is rather difficult, in that many symptoms present in ways that are common to many other bowel- and gut-related diseases. It is common that many people undergo many surgeries, sometimes over several years, to attempt to combat other possible diseases. The diagnosis itself is conducted by a physician based on multiple tests and is subjective rather than definitive, which for those who have enteric neuropathy will show signs of severe abnormalities in the movement of the gut. An operation to take a section of muscle for biopsy which, if it shows signs of nerve degradation, assists in the diagnosis.

An enterocutaneous fistula (ECF) is an abnormal communication between the small or large bowel and the skin that allows the contents of the stomach or intestines to leak through an opening in the skin.

Loss of appetite and weight loss can occur. Additional signs are weakness, sore tongue, headaches, heart palpitations, irritability, and behavioral disorders. In adults, anemia (macrocytic, megaloblastic anemia) can be a sign of advanced folate deficiency.

Women with folate deficiency who become pregnant are more likely to give birth to low birth weight premature infants, and infants with neural tube defects. In infants and children, folate deficiency can lead to failure to thrive or slow growth rate, diarrhea, oral ulcers, megaloblastic anemia, neurological deterioration. Microcephaly, irritability, developmental delay, seizures, blindness and cerebellar ataxia can also be observed.

Infection can cause subcutaneous haemorrhage that presents as reddening of the throat, mouth, gill tips, and fins, and eventual erosion of the jaw and palate. Hemorrhaging also occurs on internal organs, and in the later stages of the disease, the abdomen becomes filled with a yellow fluid - giving the fish a "pot-bellied" appearance. The fish often demonstrate abnormal behavior and anorexia. Mortality rates can be high.

A presumptive diagnosis can be made based in the history and clinical signs, but definitive diagnosis requires bacterial culture and serological testing such as ELISA and latex agglutination.

Folate deficiency is a low level of folic acid and derivatives in the body. Also known as vitamin B9, folate is involved in adenosine, guanine, and thymidine synthesis (part of DNA synthesis). Signs of folate deficiency are often subtle. Anemia is a late finding in folate deficiency and folate deficiency anemia is the term given for this medical condition. It is characterized by the appearance of large-sized, abnormal red blood cells (megaloblasts), which form when there are inadequate stores of folic acid within the body.

The mnemonic FRIENDS can be used to memorize characteristics which impede the closure of ECF.

F Foreign body

R Radiation

I Infection or Inflammatory bowel disease

E Epithelialization

N Neoplasm

D Distal obstruction

S Short tract (<2 cm)

The following is a list of common signs and symptoms found with neonatal meningitis.

- Fever

- poor appetite

- anterior fontanelle bulging

- seizure

- jitteriness

- dyspnea

- irritability

- anorexia

- vomiting

- diarrhea

- abdominal distention (increase in abdominal size)

- neck rigidity

- cyanosis

- jaundice

- and sunset eyes (downward gaze of the eyes)

- abnormal body temperature (hypo-or hyperthermia)

- change of activity (lethargy or irritability)

Unfortunately these symptoms are unspecific and may point to many different conditions.

Multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerances (IEI), is a disputed chronic condition characterized by symptoms that the affected person attributes to low-level exposures to commonly used chemicals. Symptoms are typically vague and non-specific. They may include fatigue, headaches, nausea, and dizziness.

Commonly attributed substances include scented products, pesticides, plastics, synthetic fabrics, smoke, petroleum products, and paint fumes.

Although the symptoms themselves are real, and can be disabling, MCS is not recognized as an organic, chemical-caused illness by the World Health Organization, American Medical Association, or any of several other professional medical organizations. Blinded clinical trials show that people with MCS react as often and as strongly to placebos as they do to chemical stimuli; the existence and severity of symptoms is related to perception that a chemical stimulus is present. Some attribute the symptoms to depression, somatoform disorders, or anxiety disorders.

Enteropathic arthropathy or enteropathic arthritis refers to acute or subacute arthritis in association with, or as a reaction to, an enteric (usually colonic) inflammatory condition.

Symptoms range in severity from mild to disabling.

Symptoms are common, but vague and non-specific for the condition. The most common are feeling tired, "brain fog" (short-term memory problems, difficulty concentrating), gastrointestinal problems, headaches, and muscle pain.

A partial list of other symptoms patients have attributed to MCS include: difficulty breathing, pains in the throat, chest, or abdominal region, skin irritation, headaches, neurological symptoms (nerve pain, pins and needles feelings, weakness, trembling, restless leg syndrome), tendonitis, seizures, visual disturbances (blurring, halo effect, inability to focus), anxiety, panic and/or anger, sleep disturbance, suppression of immune system, digestive difficulties, nausea, indigestion/heartburn, vomiting, diarrhea, joint pains, vertigo/dizziness, abnormally acute sense of smell (hyperosmia), sensitivity to natural plant fragrance or natural pine terpenes, dry mouth, dry eyes, and an overactive bladder.

The following diseases manifest by means of neurological dysfunction: Lambert-Eaton myasthenic syndrome, paraneoplastic cerebellar degeneration, encephalomyelitis, limbic encephalitis, brainstem encephalitis, opsoclonus myoclonus ataxia syndrome, anti-NMDA receptor encephalitis, and polymyositis.