-IBIS-1.5.0-
tx
digestive system
constipation
diagnoses
definition and etiology
definition:
difficult or infrequent bowel movements; depending on the patient and situation, constipation can be used to describe difficult stool passage requiring straining, small and/or hard stools, infrequent defecation, or a feeling of incomplete defecation;
the degree of infrequency which defines constipation is subject to varied medical opinion; naturopathic physicians and other holistic health care professionals define healthy elimination as daily at minimum (see: bowel toxemia)
etiology: acute
This represents a distinct change for the patient, and usually indicates an alteration in diet and/or lifestyle, strong stress, or an organic cause. In patients with no obvious cause and where the constipation is quite recent, a mechanical bowel obstruction should be investigated.
causes of acute constipation:
adynamic ileus: which is often seen with intra-abdominal disease, after a traumatic injury, and as a result of general anesthesia
as a side-effect of drug use (esp. aluminum hydroxide, iron salts, bismuth salts, cholestyramine, anticholinergics, opiates, sedatives and tranquilizers)
colonic tumors (when the constipation is persistent for weeks, or is gradually getting worse).
anorectal pathology: herpes simplex outbreak, fissure, etc.
etiology: chronic
Normal frequency should be an easy, full movement at least once daily. Factors influencing regularity and ease of stool passage include diet, cultural attitudes and individual colonic health and activity, insufficient dietary fiber and roughage, sedentary lifestyle, ignoring defecation urges, and frequent traveling. The voluntary suppression of the urge to defecate may arise in the child from stresses around toilet training (see "encopresis" in course/prognosis), or in the adult, from unaccustomed surroundings, unpleasant toilet facilities, a "too busy to stop" lifestyle, medications, or conditions requiring confinement to bed.
As the bowel becomes chronically full, the patient becomes less aware of rectal distention, although associated symptoms such as excessive flatulence, bad breath, and headaches may be problematic. Negative feedback then occurs as the constipated patient finally has a bowel movement that proves to be painful, unsatisfactory, and necessitates straining. The patient may become even more adverse to defecation because of the discomfort and the situation worsens (constipation-> painful stool passage-> more constipated). Often, chronically constipated patients become frequent, dependent laxative abusers, until their bowels can no longer have a movement without laxatives. Chronic constipation is much more common in women. Children with chronic constipation below the age of 16, and adults with atonic constipation, may develop an unpleasant complication known as encopresis, or soiling.
causes of chronic constipation:
depression
decreased colonic motility (e.g. scleroderma, spinal cord injury, Hirschsprung's disease)
painful anorectal pathology (e.g. hemorrhoids, fissures, abscesses, strictures, carcinoma, hernias, diverticulitis)
metabolic abnormalities (e.g. hypothyroidism, hypokalemia, dehydration, hypercalcemia)
neurologic disorders (e.g. spinal cord injury, multiple sclerosis, Parkinson's, senility)
psychological disorders
special types:
psychogenic constipation is described as an obsessive-compulsive fixation on frequency and quality of bowel movements. Unhappy with their defecation, and anxious if a day is missed, these patients often become dependent on laxatives, developing a "cathartic colon" (a colon that resembles the colon of ulcerative colitis from its lack of haustra on barium enema testing) and demonstrate melanosis coli on physical examination.
atonic constipation is associated with elderly or invalid (esp. bedridden) patients. There is a lack of normal stimuli eliciting the colon to evacuate and/or the accessory stimuli garnered by eating and physical activity; as a result, feces accumulate in the colon.
signs and symptoms
signs and symptoms:
infrequent and/or painful defecation
small, hard stools
feeling of incomplete stool passage
straining at stool
bloating, flatulence
halitosis
full tongue, broad, dry and thick
headaches
abdominal cramping
fatigue
skin problems (e.g. acne vulgaris)
decreased appetite
anxiety over poor bowel function
frequent use of laxatives
distended abdomen
abdomen tender to palpation
feces palpable in colon
decreased (or increased) bowel sounds
melanosis coli (psychogenic constipation)
ampulla full of soft feces
nontender abdomen (atonic constipation)
anorectal pathology: e.g. fissures
lab findings:
increased bowel transit time
check occult blood
barium enema
anoscope/sigmoidoscopy
other appropriate tests to rule out suspected underlying disease
complete stool analysis to check for bacteria, enzymes, etc.
course and prognosis
Unless the patient changes the lifestyle factors which usually underlie constipation, the prognosis is for chronic, persistent constipation and associated symptoms, or a patient who will become dependent on laxatives.
Chronic constipation may lead to:
fecal impaction: This may be spontaneous or follow a barium enema. The patient presents with rectal pain and spasm, and cannot defecate even with the most urgent straining. The patient may experience cramping and the passage of watery mucus or liquid feces around the impacted mass (encopresis). Rectal examination reveals a mass of feces that is often rubbery/puttylike or rock hard. Removal of the mass by the clinician affords great relief.
encopresis: incontinence of feces in a toilet-age child that is not due to an organic illness or defect. Rule out possible pathologies before making the diagnosis. The most common age of patient is 7-8, and it affects boys three times more than girls. 50% of the children have had control of their defecation before starting encopresis and 50% have never had control. One theory for the development of encopresis is mismanaged toilet training. The suggestion is that parents may try to force toilet training on a child before:
1) the child's neuromuscular system is physiologically developed
2) bowel movements have been coming at regular times
3) s/he comprehends what is expected in the training chair (potty)
4) s/he is willing to sit on the chair and attempt to defecate
With anxious, tense, strict, compulsive, bowel-fixated parents, toilet training becomes an aggravation and struggle; the child begins to hold back to avoid having to defecate. The child might develop some anorectal pathology, such as a fissure that makes stool passage painful, which creates the same cycle as in the adult. The child, ignoring the urge to defecate eventually either loses the stool or has a watery passage of material around the fecal mass (as in the adult atonic constipation). Physical exam reveals normal sphincter tone and a rectal ampulla full of feces. The child may be withdrawn or have poor neurodevelopment (poor coordination, writing/speaking deficiencies). Invasive testing should be minimal; barium enema and x-rays are not usually helpful and sigmoidoscopy should be reserved to those cases where a bowel defect is suspected. Unless a severe psychosis or neurologic condition exists, the prognosis is excellent with caring, patient treatment. The majority of children are no longer encopretic by age 16.
differential diagnosis
investigation of cause, including physiologic, mechanical, pharmacologic or behavioral
footnotes