DIARRHEA and CONSTIPATION
No body function is more variable and subject to extraneous influences than is
defecation
influences - social, dietary , cultural patterns
individual physiologic factors - normal bowel habits vary from person to person subjective view on this habit
diarrhea and constipation as disease alone, or accompaning other disorders
in an urban civilization, normal bowel frequency ranges from 2 to 3/ day to
2 to 3/week
Changes in stool frequency, consistency, or volume, or blood, mucus, pus, or excess fatty
material ( eg. oil, grease, film) in the stool may indicate disease
DIARRHEA - increased volume, fluidity, or frequency
of fecal discharges
there is not easy and unique definition - it is rather symptom
increased number of defecation a more fluiditiy of stool than usually in individual person
in our society, the stool weight of healthy adults ranges from 100 to 300 gr/ day
Persons whose diet is rich in vegetable fiber weight is higher
since 60 to 90% of stool weight is water - diarrhea is mainly due to excess fecal water
daily comes to the bowel about 8-9 l fluid ( 2l from the food, the rest are digestive secreta,
only approxim. 1.5l comes to colon
usually only 100 ml of water leaves with the stool from the body
reserve capacity of the large bowel is 4 l
- than starts diarrhea
„intrinsic diarrhea „
under the term of diarrhea we can also understand as malabsorption of water and electrolytes
Pathogenesis:
1. Osmotic diarrhea - occurs when nonabsorbable, water-soluble solutes remain in the
bowel where they retain water.
This occurs with
1. lactose (lactase deficiency) and other sugar intolerances,
poorly absorbed salts ( magnesium sulfate, sodium phosphates)
hexitols, sorbitol and mannitol -dietetic foods, chewing gum
2. if it is overgone bowel capacity for the back resorption, it occurs diarrhea, the volume of
the stool is usually lower than by sectretory diarrhea,
the condition disappears as soon as intake stops
3. many mucosal diseases ( eg. regional enteritis, ulcerative colitis, TB, lymphoma and
carcinoma can cause an exudative diarrhea - enteropathy
mucosal changes ( inflammation, ulceration or edemas may result in an outpouting of
plasma, serum proteins, blood, mucus, thus increasing fecal bulk and fluidity
2. Secretory diarrhea - may occur when the small and large bowel secrete rater than absorb
electrolytes and water
water depletion is over 10 ml/ kg of weight / 24 hours
does not stop as intake stops
eg: bile acids after ileal resection
unabsorbed dietary fat in steatorrhea
castor oil, antraquinone cathartics
some prostaglandines, vasoactive intestinal peptide - VIP
infections - bacterial toxin - cholera, enteropahogenic viruses
3. Combination of both mechanisms if the unarbsorbed material is abundant, water -soluble and osmotically important ( ie. of
low mol wt) the mechanism could be osmotic
Lipids are not appreciably water-soluble and cannot act this way - some ( fatty acids, bile
acids ) act as secretagogues for electrolytes and water
e.g.: in nontropical sprue - fat malabsorption ( causing colonic secretion ) and
carbohydrate malabsorption ( causing osmotic diarrhea) can coexist
4. Altered intestinal transit
For normal absorption, chyme must be exposed to adequate absorptive surface of the GI tract
for a sufficient amount of time
Factors that decrease exposure time:
small or large bowel resection
gastric resection, pyloroplasty, vagotomy
surgical bypass of intestinal segments
drugs or humoral agents ( prostaglandins, serotonin) that speed transit by stimulatin intestinal
smooth muscle
Increased exposure time and bacterial overgrowth:
strictures of bowel segments
sklerodermatous intestinal disease
stagnant loops created by surgery
Division according to course of disease:
Acute diarrhea
nutritive
antibiotics ( pseudomembranouse colitis
Chronic diarrhea
most of organic disorders of small and large bowel ( proctocolitis, m. Croh, colorectal
carcinoma, celiacal sprue, colon iritabile
extra bowel tract:: achlorhydria or extrem hyperacidity, stp. gastric resection
stp. CHE, stp. vagotomy, carcinoid, sy Verner-Morrison
extra gastrointestinal tract : hyperthyreoidism, medullar thyroid Ca, adrenal cortex
insuficiency, diabetic vegetatitve neuropathy, bronchogenous carcinoma ( VIP secretion)
exogenous intoxikation -mercury, lead
endogenous - uremia ( Treitz colitis )
Complications of diarrhes
chronic x acute
electrolyte loss ( na,K,Mg,Cl), fluid loss with consequent dehydration and vascular collapse
may occur
COLLAPSE - can be acute, especially in children and very old or attenuated persons or
extreme heavy diarrhea e.g. cholera
METABOLIC ACIDOSIS - due to HCO3 loss
HYPOKALEMIA - very severe or chronic diarrhea , or if stool contain excess mucus
HYPOMAGNESEMIA - tetany
MALNUTRITION
HYPOVITAMINOSIS
Diagnosis
Clinical features vary greatly depending on the cause , duration, and severity of the diarrhea,
on the area of bowel affected and on the patient´s general health
HISTORY:: time, place and conditions of the diarrhea origin, dietary factors,
used medicaments
duration, accompanied pain, other symptoms: vomiting, blood in
stool, appearence of the stool, rectal tenesms
EXAMINATION: physical, + per rectum !!!
stool examination - macroscopic, microscopic, cultivation
laboratory - biochemical, hematological
visualize methods : irrigoscopy, irrigography, pssage through the
small bowel, enteoclysis, defecation proctography, transit time
endoscopic methods: gastroscopy, enteroscopy, coloscopy
endoscopic biopsy, capsule biopsy of small intestine
TREATMENT
according to etiology
course ( chronic x acute)
and some trimes contemporary symptomatic therapy
correction of fluids intake - rehydration, keeping of adequaete nutrition
CONSTIPATION
difficult or infrequent passage of feces.
Can also refer to hardness of stool or feeling of incomplete evacuation
Constipation as the symptom:
causes:
mechanical - tumors, stenosis, hernia
endokrinologic and metabolic - hypothyreosis, hyperparathyreosis,
hypokalemia ,dehydration
neurogenous - agangliosis, spinal lesions, sclerosis multiplex, parkinsonism
medicaments - antacids ( ca carbonicum, Al a Bi compounds), anticholinergics,
antidepresives, hypotensives, opiates, codein
painfuls anal diseases - fissura ani , perianal absces
reflectory evocated constipation - peptic ulcer, urolithiasis
Constipation as the disease:
Habitual - depends on food, mobility, suppresion of defecation, constitucional
habits
psychogenic - many persons incorrectly believe that daily defecation is necessary and
complain of constipation becouse bowel frequency is less than they expect.
Others may be concerned with the appearence or consistency of stools, sometimes is major
complaint - is lack of satisfaction with the act of defecation
as a result - they abuse the colon with laxatives, suppositories and enemas
overzealous treatment of an „ imaginary „ disorder can result in „ real „ illness eg. cathartic
colon ( pipestem - colon lacking haustra) or melanosis coli ( deposits of pigment in mucosa
obscession , depression
ACUTE constipation - represents a definite change for that individual
mechanical bowel obstruction
adynamic ileus ( accompanies acute intra-abdominal disease) - localized peritonitis,
diverticultitis
traumatic conditions ( eg. head injuries, spinal fractures)
may follow general anesthesia
in bedridden patients
many agents ( AlOH, bismuth salts, iron salts, cholestyramine, anticholinergics, opioids,
ganglionic blockers and many tranquilizers and sedatives
„ Subacute „
the change of bowel habit persists for weeks or occurs intermittently with increasing
frequency and /or severity - colonic tumors and other causes of partial obstruction sholld be
suspected
Underlying causes must be identified and treated
CHRONIC the common functional causes are those that hamper normal bowel movements because
storage, transport and evacuation mechanisms of the colon are deranged, sometimes by
systemic disorders
eg. debilitating infections, hypothyreoidism, hypercalcemia, uremia or porphyria
local neurogenic disorders - eg. iritable bowel syndrome
megacolon - syndrome with different causes:
Hirschprung´s disease - caused by congenital absence of Meissner´s and Auerbach´s
autonomic plexuses in the bowel wall - most commonly anal part of colon
Idiopatic megacolon
secondary , aquaired megacolon = colon dilatation anal, rectal stenosis, lesions of
spinal cord, hypokalemia,hypotyreodism, morphinists
neurologic disorders - Parkinson´s disease, cerebral thrombosis, tumors, injury of spinal cord
colonic inertia ( atonic constipation, colon stasis, inactive colon )
diminished colonic peristalsis, or rectal insensivity to fecal
masses
mostly aged or invalid patients, especially bedridden
the colon does not respond to the usual stimuli promoting evacuation, or
accessory stimuli normaly provided by eating and physical activity are
lacking
sometimes occurs in patients whose restal sensitivity to the presence of fecal masses
is dulled by habitual disregard of the urgento defecate, or by prolonged dependence on
laxatives or enemas, often initiated in childhoo
dyschezia - disordered evacuation, dysfunction of pelvic floor/anal sphincters
difficulty in defecation due to lack of coordination of pelvic floor muscles and anal
sphincters
causes: rectocele, enterocele, rectal ulcer, rectal prolapse
TREATMENT of CONSTIPATION
accordig to causes of constipation
diet should contain enough fiber - fruits, vegetable, enough liquids
defecation reflex trainning
relaxation exercises of anal sphincters and muscle of pelvic floor
enemas
laxatives and cathartics - wetting agents, mineral oils
osmotic agents - usually used to prepare patients for some diagnostic bowel
procedures and occasionally in the therapy of parasitic infection / phosphate, magnesium,
sulfate ionts , polyethylen glyco-electrolyte solutions l
secretory or stimulant agents : - senna and its derivates, ,
phenolphtalein, castor oil act by irritation of the intestinal mucosa or by
direct neuronal stimulation. Some are absorbed, metabolised in liver and returned to the bowel
in bile -enterohepatal circulation, increase of peristalsis and intraluminal fluid
manual evacuation of stool