According to WHO report, infant mortality due to diarrhoea is around 40%. In India, it is the leading cause of death in children below three years. Roughly, every pre-school child suffers two or four attacks of diarrhoea in a year with a mortality of 1 to 4%. Mortality is higher among low- income group families.
Diarrhoea is a symptom characterised by frequent passage of loose and abnormal stools. If blood and mucus are present, it is dysentery. Diarrhoea may be acute, recurrent and chronic. It may be mild, self-limited or severe with high fever, dehydration and collapse.
Over 80% of acute diarrhoea occurs in infants and children below three years. The incidence declines in the older age group.
The predisposing factors are flies, open-air disposal of faeces, malnutrition, poverty, poor hygiene, lack of safe drinking water, ignorance and superstition. In India, religious congregations, “melas”, open-air wayside eating restaurants, are responsible for epidemics.
In malnourished infants, immunological incompetence is another important factor causing high mortality and frequent attacks. Infective diarrhoea is rare in breast-fed infants as mother’s milk contains anti- infective antibodies like ig A and Ig D.
Infective diarrhoea is common among bottle-fed infants. Hence greater emphasis should be placed on breast-feeding. Rather feed the mother as well as possible. Diarrhoeas may occur due to anteral infection as well as parenteral causes.
(1) E. coli is the commonest bacteria in all age groups. E.coli of different sero-type cause epidemics in nurseries, hospitals, schools and residential hostels. This type of E.coli is invasive as in case of shigella, producing inflammation of intestines and stools contain blood and mucus. Another type of E.coli releases entero-toxic agent like V. cholera. It is not invasive.
(2) Shigella group e.g. Shigella Flexner, Sh. Boyd, Sh. Shigella, Sh. sonna.
(3) Salmonella group is responsible for seasonal diarrhoea and carrier state, e.g. S.Typhi, S.Para-typhi, S.typhimurium, S. enteridis, S. Hidelberg and S. Newport.
(4) Staphylococcal infection occurs in bigger children due to food poisoning and through carriers, prolonged administration of antibiotics is another cause encouraging super infection.
(5) V. Cholera and El tor Vibrio cause epidemics of cholera. Occasionally, Klebsiella proteus, pseudomonas, pyocyaneous etc. may cause diarrhoea. In cold countries campylobactor which is a vibrio causes abdominal pain and diarrhoea due to consumption of infected chicken flesh.
(6) Viral: Influenza, poliomyelitis, measles, adeno-viruses, rota-virus and coxsackie virus may cause diarrhoea.
(7) Parasitic: E. histolytica, giardia lambia, round worms, tapeworm, threadworm, hookworm also strongloides stercoralis and trichuris trichura cause acute recurrent and chronic diarrhoea in children, especially in school-going age group. Malaria may produce acute diarrhoea with blood and mucus in stool.
(8) Fungal: Candida albicans causes thrush and diarrhoea among neonates especially among bottle-fed.
Pneumonia, meningitis, urinary tract infection, mastoiditis, and septicaemia may cause acute diarrhoea. Septicaemia is a cause of diarrhoea, especially in low-birth-weight babies.
When colostrum changes to normal mother’s milk and when meconium changes to stools, there may be frequent stools in the neonates. This is physiological diarrhoea and needs no treatment.
In the underfed babies there may be hunger diarrhoea. The stools are frequent, small, greenish and sticking to the diapers.
In over-fed babies there may be frequent large stools, while excessive sugars, fats and fatty acids, spicy foods may cause diarrhoea. Recurrent diarrhoea may be due to food intolerance or food allergy; milk, wheat-gluten, fish, egg and groundnut may cause allergic diarrhoea in some children.
The incidence of acute diarrhoea increases during weaning period (weaning diarrhoea).
Like hyperthyroidism, hypoparathyroidism, and adrenal tumour may cause acute diarrhoea in older children.
Broad spectrum antibiotics and many other drugs cause changes in bacterial flora producing diarrhoea (due to staphylococci and Candida).
Rarely, pseudomonas entero-colitis may occur, diarrhoea being severe and prolonged.
In older children nervous tension, anxiety, depression and fear cause diarrhoea. Often there is family history. Post-prandial diarrhoea belongs to this group.
Hirschprungs diseases may cause diarrhoea in neonates and necrotising enterocolitis is also a rare cause.
Causes of Neonatal Diarrhea:
(1) Physiological diarrhoea
(2) Parenteral infection and deep sepsis
(3) E.Coli infection
(4) Lactose intolerance
(5) Unconjugated bile-acid diarrhoea
(7) Milk allergy
(8) Congenital chloridorrhoea
(9) Necrotising enterocolitis
(10) Hirschprung’s disease
Causes of chronic diarrhoea Common causes are:
(1) Amoebic dysentry
(3) Disaccharidase deficiency
(4) All causes of recurrent diarrhoea
Causes of Recurrent Diarrhoea:
(1) Amoebiasis and giardiasis
(2) Malabsorption syndrome e.g. coeliac diseases and fibrocystic disease of the pancreas, protein-losing enteropathy
(3) Abdominal tuberculosis
(4) Ulcerative colitis
(5) Crohn’s disease
(6) Cirrhosis of liver
(7) Immunological deficiency with malnutrition.
Clinical Features of Acute Diarrhoea:
The biochemical changes are always more important. The fundamental disturbance lies in loss of water and electrolytes, causing dehydration, which may be isotonic, hypotonic, and hypertonic depending on the proportion of water and salts loss. In isotonic dehydration the ratio of electrolytes to water is undisturbed though their sum total in body fluids is reduced.
When more water than electrolytes is lost hypernatraemia or hypertonic dehydration occurs. While if more salt then water is lost then hypotonic especially among malnourished children and 15% are hypertonic.
Dehydration may be mild, moderate and severe.
In Mild Cases:
The child loses 5% body weight, may pass 5-6 stools, is pale irritable, with slightly sunken eyes and fontanelle (if not closed). Tongue is still moist, acidosis is not noticeable, stool may be green or yellow.
Moderate Cases: (Loss of Weight — 5% to 10%):
Stools may be 10 or more, child is ill, irritable or drowsy, with sunken eyes and fontanelle with dry mucous membrane and inelastic skin. If the skin on the abdomen is pinched it very slowly retracts to the surface. Acidosis is usually present, though not marked.
Sever Cases: (Loss of Body Weight is More Than 10%):
There are too many loose motions with marked constitutional symptoms like shock and peripheral failure. The pulse is thready and rapid with low blood pressure. There is oliguria or anuria. Eyes are sunken, marked depression of fontanelle. The abdominal skin is inelastic.
Breathing is deep and rapid due to acidosis. There may be convulsion. If the loss of body weight is more than 15% the condition becomes irreversible with all the previous symptoms being more marked. The child is in coma with anoxia; abdomen is sunken or in case of hypokalaemia there may be distension and tympanitis resulting in paralytic ileus. Plasma sodium level is less than 130 m Eq/L.
The extracellular fluid is hypotonic. To maintain electrolyte balance there is shift of water to intracellular compartment resulting in oedema of brain and liver tissue and there is more loss of potassium, and bicarbonate by the kidneys. The child is first drowsy, then comatose with convulsion. Thirst is absent. Tongue may be moist.
Plasma sodium exceeds 150 m. Eq/L E.C.F. fluid is hypertonic; to maintain electrolyte balance water shifts from cells into extracellular compartment resulting in shrinkage of brain cells. Hence subdural and intracerebral haemorrhage may occur.
The child in hyperirritable and has profound thrist. All the signs of dehydration are exaggerated and there may be hyperpyrexia.
In acute diarrhoea this is quite common due to loss of potassium with stools and due to vomiting, acidosis and toxaemia. The child is lethargic and flabby with hypotonia of muscles, loss of deep reflexes, distension of abdomen with marked tympanitis resulting in paralytic ileus; there is tachycardia with characteristic ECG charges.
Here the CO2 combining power is lower than 20 m. Eq. per litre. In severe acidosis, the child is drowsy and respiration is deep and may be 80-100 per minute, urine may contain ketone bodies.
The sequelae of recurrent and chronic diarrhoea are:
a. Growth failure
c. Immunological deficiencies
d. Prolapse of rectum
e. Psychological changes in the child.
Routine examination of stools, macroscopic and microscopic examination is sufficient for starting treatment. For etiological diagnosis well-equipped laboratory is required for stool culture with sensitivity tests, estimation of Na, K, CO2 combining power and other electrolytes Hb concentration, blood urea and creatinine etc.
Remember Five “D“s:
(1) Diagnosis (aetiological) as far as possible
(2) Dehydration should be assessed
(5) Disaccharidases deficiency must be watched.
Nowadays the emphasis is on domiciliary treatment rather than hospitalisation mild and moderate cases can be treated at home; present experiences show that oral hydration if started with the onset of any diarrhoea may prevent the child from getting into severe stage.
What is required is the health education emphasising oral hydration in rural areas and urban slums in our country. Hospitalisation is required for severe cases with shock and peripheral failure and marked acidosis. If parenteral therapy is required for moderate cases this can be done at home with scalp vein canula, which is now available.
The WHO formulation oral hydration is:
Sodium chloride 3.5 gm
Sodium bicarbonate 2.5 gm
Pot. Chloride 1.5 gm
Glucose 25 gm
To be dissolved in 1 litre of boiled water. Many preparations conforming to the formula are now available in the market. According to WHO, children rehydrated with oral solution have their appetite restored quickly and improve their nutritional state. In rural areas mothers may be instructed to dissolve in one litre of boiled water one level teaspoon (about seven pinches) of dry common salt and enough sugar to sweeten and use this fluid.
Oral fluids 10-20 cc/kg/hour may be given for 48 hours by which time dehydration is virtually controlled. Even where parenteral therapy is given, the maintenance therapy can be continued with oral hydration. Once the child can take fluid by oral route 30 cc to 60 cc oral fluid is given after every stool is passed.
Where parenteral fluid is to be given isotonic saline with 5% glucose M/6 lactate solution or Ringer lactate or Hartman’s solution are given as indicated.
Fluid Requirement of Acutely Dehydrated Children:
Commonly 5% glucose in half normal saline is used to combat acute dehydration.
Usual method is to give 120 to 200 ml/kg in 24 hours intravenously but in severe cases 45 to 60 ml/kg is given in first four hours of treatment.
However, in the new-born it may be safer to use a quarter strength saline after initial treatment with half-normal glucose for 12 to 24 hours.
When severe metabolic acidosis is present 1/6 molar lactate should be given to start with 30 ml/kg body weight, which may be repeated after a few hours if acidosis persists (assessment is by Astrup micromethod). Each ml. of 8.4% sodium bicarbonate is 1 mEq.
The bicarbonate requirement may be roughly calculated as follows:
Body weight in kg X 0.35 X base deficit in m. Eq/hour (considering that 35% of B.W is extracellular fluid).
Potassium deficiency is correctable by oral K-salt but in severe cases specially where vomiting continue, intravenous potassium chloride may be necessary. Hypertonic dehydration and water intoxication are sometimes real problems.
If vomiting does not stop or if there is abdominal distension and intestinal hurry, parenteral therapy has to be continued till the child can take fluid orally. When isotonic solution is used for initial therapy intravenously, potassium should be given orally 1-3 gm daily. In severe hypopotassaemia, potassium has to be given by I. V. drip in 1-3 mEq/kg dose. In hyperpotassaemia digoxin, insulin and calcium are of value. For hyponatraemia with 3% NaCl in 5% glucose may be followed by isotonic saline while monitoring of electrolytes should be done. Frequent electrolyte studies are essential to properly tract these cases.