The psychiatric (DSM-IV) diagnostic criteria for encopresis are:

1. Repeated passage of feces into inappropriate places (e.g., underwear or floor) whether voluntary or unintentional

2. At least one such event a month for at least 3 months

3. Chronological age of at least 4 years (or equivalent developmental level)

4. The behavior is not exclusively due to a physiological effect of a substance (e.g., laxatives) or a general medical condition, except through a mechanism involving constipation.

The DSM-IV recognizes two subtypes: with constipation and overflow incontinence, and without constipation and overflow incontinence. In the subtype with constipation, the feces are usually poorly formed and leakage is continuous, and this occurs both during sleep and waking hours. In the type without constipation, the feces are usually well-formed, soiling is intermittent, and feces are usually deposited in a prominent location. This form may be associated with oppositional defiant disorder (ODD) or conduct disorder, or may be the consequence of large anal insertions, or more likely due to chronic encopresis that has radically desensitized the colon and anus.

FI affects virtually all aspects of peoples' lives, greatly diminishing physical and mental health, and affect personal, social and professional life. Emotional effects may include stress, fearfulness, anxiety, exhaustion, fear of public humiliation, feeling dirty, poor body-image, reduced desire for sex, anger, humiliation, depression, isolation, secrecy, frustration and embarrassment. Some people may need to be in control of life outside of FI as means of compensation. The physical symptoms such as skin soreness, pain and odor may also affect quality of life. Physical activity such as shopping or exercise is often affected. Travel may be affected, requiring careful planning. Working is also affected for most. Relationships, social activities and self-image likewise often suffer. Symptoms may worsen over time.

Encopresis (from the Ancient Greek ἐγκόπρησις / egkóprēsis), also known as paradoxical diarrhea, is voluntary or involuntary fecal soiling in children who have usually already been toilet trained. Children with encopresis often leak stool into their undergarments.

This term is usually applied to children, and where the symptom is present in adults, it is more commonly known as fecal leakage (FL), fecal soiling or fecal seepage.

Fecal incontinence (FI), also known as anal incontinence, or in some forms encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents—including flatus (gas), liquid stool elements and mucus, or solid feces. FI is a sign or a symptom, not a diagnosis. Incontinence can result from different causes and might occur with either constipation or diarrhea. Continence is maintained by several inter-related factors, including the anal sampling mechanism, and usually there is more than one deficiency of these mechanisms for incontinence to develop. The most common causes are thought to be immediate or delayed damage from childbirth, complications from prior anorectal surgery (especially involving the anal sphincters or hemorrhoidal vascular cushions) and altered bowel habits (e.g., caused by irritable bowel syndrome, Crohn's disease, ulcerative colitis, food intolerance, or constipation with overflow incontinence). An estimated 2.2% of community dwelling adults are affected.

Fecal incontinence has three main consequences: local reactions of the perianal skin and urinary tract, including maceration (softening and whitening of skin due to continuous moisture), urinary tract infections, or decubitus ulcers (pressure sores); a financial expense for individuals (due to cost of medication and incontinence products, and loss of productivity), employers (days off), and medical insurers and society generally (health care costs, unemployment); and an associated decrease in quality of life. There is often reduced self-esteem, shame, humiliation, depression, a need to organize life around easy access to bathroom and avoidance of enjoyable activities. FI is an example of a stigmatized medical condition, which creates barriers to successful management. People may be too embarrassed to seek medical help, and attempt to self-manage the symptom in secrecy from others.

FI is one of the most psychologically and socially debilitating conditions in an otherwise healthy individual, but it is generally treatable. Management may be achieved through an individualized mix of dietary, pharmacologic, and surgical measures. Health care professionals are often poorly informed about treatment options, and may fail to recognize the effect of FI.

Symptoms include chronic constipation. There can be fecal incontinence and paradoxical or overflow diarrhea (encopresis) as liquid stool passes around the obstruction. Complications may include necrosis and ulcers of the rectal tissue. Abdominal pain and bloating could also be present depending on the severity of the condition. Loss of appetite can also occur.

Symptoms include:

- Straining to pass fecal material

- Tenesmus (a feeling of incomplete evacuation)

- Feeling of anorectal obstruction/blockage

- Digital maneuvers needed to aid defecation

- Difficulty initiating and completing bowel movements

Constipation is a symptom, not a disease. Most commonly, constipation is thought of as infrequent bowel movements, usually less than 3 stools per week. However, people may have other complaints as well including:

- Straining with bowel movements

- Excessive time needed to pass a bowel movement

- Hard stools

- Pain with bowel movements secondary to straining

- Abdominal pain

- Abdominal bloating.

- the sensation of incomplete bowel evacuation.

The Rome Criteria are a set of symptoms that help standardize the diagnosis of constipation in various age groups. These criteria help physicians to better define constipation in a standardized manner.

There are many different types of rectal discharge, but the most common presentation of a discharge is passage of mucus or pus wrapped around an otherwise normal bowel movement.

Rectal discharge has many causes, and may present with other symptoms:

- Staining of undergarments

- Constant feeling of dampness around anus

- Frequent urge to open bowels, but passage of only small amounts of mucus or pus-like liquid rather than normal feces

- Rectal pain

- Rectal malodor, when the discharge is foul-smelling, e.g. associated with certain infections

- Pruritus ani

- Rectal bleeding

- Perianal erythema, swelling and tenderness

Anismus (or dyssynergic defecation) refers to the failure of the normal relaxation of pelvic floor muscles during attempted defecation.

Anismus can occur in both children and adults, and in both men and women (although it is more common in women). It can be caused by physical defects or it can occur for other reasons or unknown reasons. Anismus that has a behavioral cause could be viewed as having similarities with parcopresis, or psychogenic fecal retention.

Symptoms include tenesmus (the sensation of incomplete emptying of the rectum after defecation has occurred) and constipation. Retention of stool may result in fecal loading (retention of a mass of stool of any consistency) or fecal impaction (retention of a mass of hard stool). This mass may stretch the walls of the rectum and colon, causing megarectum and/or megacolon, respectively. Liquid stool may leak around a fecal impaction, possibly causing degrees of liquid fecal incontinence. This is usually termed encopresis or soiling in children, and fecal leakage, soiling or liquid fecal incontinence in adults.

Anismus is usually treated with dietary adjustments, such as dietary fiber supplementation. It can also be treated with a type of biofeedback therapy, during which a sensor probe is inserted into the person's anal canal in order to record the pressures exerted by the pelvic floor muscles. These pressures are visually fed back to the patient via a monitor who can regain the normal coordinated movement of the muscles after a few sessions.

Some researchers have suggested that anismus is an over-diagnosed condition, since the standard investigations or digital rectal examination and anorectal manometry were shown to cause paradoxical sphincter contraction in healthy controls, who did not have constipation or incontinence. Due to the invasive and perhaps uncomfortable nature of these investigations, the pelvic floor musculature is thought to behave differently than under normal circumstances. These researchers went on to conclude that paradoxical pelvic floor contraction is a common finding in healthy people as well as in people with chronic constipation and stool incontinence, and it represents a non-specific finding or laboratory artifact related to untoward conditions during examination, and that true anismus is actually rare.

Different types of discharge are described. Generally "rectal discharge" refers to either a mucous or purulent discharge, but, depending upon what definition of rectal discharge is used, the following could be included:

- Purulent rectal discharge

- Mucous rectal discharge

- Watery rectal discharge

- Steatorrhoea ("fatty diarrhea" caused by excess fat in stools, or an oily anal leakage)

- Keriorrhea (orange oily anal leakage caused by high levels of escolar and oilfish in the diet)

- Rectal bleeding, melena and hematochezia

- Feculent rectal discharge (fecal rectal discharge), e.g. fecal leakage, encopresis and incontinence of liquid stool elements

- Diarrhea

A fecal impaction is a solid, immobile bulk of human feces that can develop in the rectum as a result of chronic constipation. A related term is fecal loading which refers to a large volume of stool in the rectum of any consistency.

Constipation refers to bowel movements that are infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement. Complications from constipation may include hemorrhoids, anal fissure or fecal impaction. The normal frequency of bowel movements in adults is between three per day and three per week. Babies often have three to four bowel movements per day while young children typically have two to three per day.

Constipation has many causes. Common causes include slow movement of stool within the colon, irritable bowel syndrome, and pelvic floor disorders. Underlying associated diseases include hypothyroidism, diabetes, Parkinson's disease, celiac disease, non-celiac gluten sensitivity, colon cancer, diverticulitis, and inflammatory bowel disease. Medications associated with constipation include opioids, certain antacids, calcium channel blockers, and anticholinergics. Of those taking opioids about 90% develop constipation. Constipation is more concerning when there is weight loss or anemia, blood is present in the stool, there is a history of inflammatory bowel disease or colon cancer in a person's family, or it is of new onset in someone who is older.

Treatment of constipation depends on the underlying cause and the duration that it has been present. Measures that may help include drinking enough fluids, eating more fiber, and exercise. If this is not effective, laxatives of the bulk forming agent, osmotic agent, stool softener, or lubricant type may be recommended. Stimulant laxatives are generally reserved for when other types are not effective. Other treatments may include biofeedback or in rare cases surgery.

In the general population rates of constipation are 2–30 percent. Among elderly people living in a care home the rate of constipation is 50–75 percent. People spend, in the United States, more than on medications for constipation a year.

The pathophysiology of the condition results from neuronal plasticity associated with bladder afferents and motor neurons innervating the external urethral sphincter. People with this condition generally experience daytime and night time wetting, urinary retention, and often have a history of urinary tract and bladder infections. Constipation and encopresis are often associated with this condition.

The small intestine consists of the duodenum, jejunum and ileum. Inflammation of the small intestine is called enteritis, which if localised to just part is called duodenitis, jejunitis and ileitis, respectively. Peptic ulcers are also common in the duodenum.

Chronic diseases of malabsorption may affect the small intestine, including the autoimmune coeliac disease, infective Tropical sprue, and congenital or surgical short bowel syndrome. Other rarer diseases affecting the small intestine include Curling's ulcer, blind loop syndrome, Milroy disease and Whipple's disease. Tumours of the small intestine include gastrointestinal stromal tumours, lipomas, hamartomas and carcinoid syndromes.

Diseases of the small intestine may present with symptoms such as diarrhoea, malnutrition, fatigue and weight loss. Investigations pursued may include blood tests to monitor nutrition, such as iron levels, folate and calcium, endoscopy and biopsy of the duodenum, and barium swallow. Treatments may include renutrition, and antibiotics for infections.

Diseases that affect the large intestine may affect it in whole or in part. Appendicitis is one such disease, caused by inflammation of the appendix. Generalised inflammation of the large intestine is referred to as colitis, which when caused be the bacteria "Clostridium difficile" is referred to as pseudomembranous colitis. Diverticulitis is a common cause of abdominal pain resulting from outpouchings that particularly affects the colon. Functional colonic diseases refer to disorders without a known cause, and include irritable bowel syndrome and intestinal pseudoobstruction. Constipation may result from lifestyle factors, impaction of a rigid stool in the rectum, or in neonates, Hirschprung's disease.

Diseases affecting the large intestine may cause blood to be passed with stool, may cause constipation, or may result in abdominal pain or a fever. Tests that specifically examine the function of the large intestine include barium swallows, abdominal x-rays, and colonoscopy.

Bladder sphincter dyssynergia (also known as detrusor sphincter dysynergia (DSD) (the ICS standard terminology agreed 1998) and neurogenic detrusor overactivity (NDO)) is a consequence of a neurological pathology such as spinal injury or multiple sclerosis. which disrupts central nervous system regulation of the micturition (urination) reflex resulting in dyscoordination of the detrusor muscles of the bladder and the male or female external urethral sphincter muscles. In normal lower urinary tract function, these two separate muscle structures act in synergistic coordination. But in this neurogenic disorder, the urethral sphincter muscle, instead of relaxing completely during voiding, dyssynergically contracts causing the flow to be interrupted and the bladder pressure to rise.

Thorough history regarding frequency of bedwetting, any period of dryness in between, associated daytime symptoms, constipation, and encopresis should be sought.

The medical name for bedwetting is "nocturnal enuresis". The condition is divided into 2 types: primary nocturnal enuresis (PNE) and secondary nocturnal enuresis.

Children with a tic disorder may exhibit the following symptoms:

- overwhelming urge to make movement

- jerking of arms

- clenching of fists

- excessive eye blinking

- shrugging of shoulders

- kicking

- raising eyebrows

- flaring of nostrils

- production of repetitive noises such as grunting, clicking, moaning, snorting, squealing, or throat clearing

Separation anxiety disorder

- excessive stress when separated from home or family

- fear of being alone

- refusal to sleep alone

- clinginess

- excessive worry about safety

- excessive worry about getting lost

- frequent medical complaints with no cause

- refusal to go to school

Selective mutism

- unable to speak in certain social situations, even though they are comfortable speaking at home or with friends

- difficulty maintaining eye contact

- may have blank facial expressions

- stiff body movements

- may have a worrisome personality

- may be incredibly sensitive to sound

- difficulty with verbal and non-verbal expression

- may appear shy, when in reality, they have a fear of people.

Reactive attachment disorder of infancy or early childhood

- withdrawing from others

- aggressive attitude towards peers

- awkwardness or discomfort

- watching others but not engaging in social interaction

Stereotypic movement disorder

- head banging

- nail biting

- hitting or biting oneself

- hand waving or shaking

- rocking back and forth