University of Zambia Medical Library

The Outpatient Management of Bloody Diarrhoea in Young Children

Bloody diarrhoea in a young child is usually a sign of a serious invasive bacterial infection of the bowel. Pathogens that cause bloody diarrhoea may also cause diarrhoea without visible blood, but such episodes are less severe, generally resembling diarrhoeal disease caused by non-invasive pathogens. The presence of visible blood is, thus, a convenient and reliable indicator of severity.

The correct treatment of bloody diarrhoea includes: (i) giving an antimicrobial that is effective against Shigella, (ii) giving oral rehydration salts (ORS) solution or other fluids to prevent or treat dehydration, (iii) continuing to feed the child, and (iv) providing follow-up, especially for children at increased risk of serious morbidity or death. When these steps are followed, most episodes of bloody diarrhoea resolve rapidly and many serious consequences are avoided.

Definitions:
Bloody diarrhoea refers to a diarrhoeal episode in which the stools contain visible red blood. It is the preferred term to describe this problem. Dysentery has the same meaning as bloody diarrhoea. Although sometimes used to describe bloody diarrhoea that is associated with fever, abdominal cramps, rectal pain and mucoid stools, these features do not always accompany bloody diarrhoea, nor does their presence or absence necessarily define its etiology or determine how it should be treated.

Causes of bloody diarrhoea:
Invasive bacteria -- Shigella are the most important cause of bloody diarrhoea among young children in developing countries. Shigella cause 50% or more of all episodes of bloody diarrhoea, a much higher proportion of episodes that are clinically severe, and most of the estimated 370 000 deaths from bloody diarrhoea that occur worldwide each year in children younger than five years.

Episodes of bloody diarrhoea caused by other bacterial pathogens occur less frequently than shigellosis, are usually less serious, and their cause is often difficult to determine except in research laboratories. These bacteria include: Campylobacter jejuni, enteroinvasive Escherichia coli, entero-haemorrhagic E. coli and non-typhoid serotypes of Salmonella.

Entamoeba histolytica -- Amoebiasis is an uncommon cause of bloody diarrhoea in young children. A study done in China, India, Mexico, Myanmar and Pakistan involving 3640 children under three years of age with acute diarrhoea yielded only 10 cases of probable invasive amoebiasis (1.5% of all episodes of bloody diarrhoea), but 400 cases of all episodes of bloody diarrhoea). In Bangladesh, a study of 101 children with bloody diarrhoea (mean age 21 months) revealed none with E. histolytica trophozoites in their stool.

Diagnosis:
Bloody diarrhoea is diagnosed by asking the mother whether the child's stool contains red blood or by looking at the stool. These methods are equally sensitive and precise. However, asking the mother is usually more efficient than waiting for the child to pass a stool. Culturing the stool is of little value because many invasive bacteria require special culture media, unusual growth conditions, or diagnostic antisera that are often unavailable. Also, attempts to isolate Shigella may fail unless the specimen is inoculated immediately and properly transported to the laboratory. Moreover, the results of culture are available only after two or three days, whereas treatment must be decided upon when the child is first seen.

The diagnosis of invasive amoebiasis requires that typical trophozoites of E. histolytica containing red blood cells be seen in the stool by a reliable technician. However, even experienced technicians frequently mistake non-pathogenic protozoa, white blood cells, macrophages containing red blood cells or partially digested vegetable matter for amoebic trophozoites. Where the skill of technicians is not confirmed by regular quality control procedures, amoebiasis is routinely over-diagnosed and laboratory reports are of little value. The detection only of amoebic cysts is not evidence of invasive amoebiasis.

Treatment of the child with bloody diarrhoea:

• Refer immediately to hospital any child with bloody diarrhoea who is severely malnourished. These are children whose weight-for-age is less than 60%, or weight-for-length is less than 70%, of the National Center for Health Statistics (NCHS) medians. Such children are at very high risk of serious complications and death.
• Treat all cases promptly with an oral antimicrobial known to be effective against most local Shigella strains. Provide enough to lastfive days and instruct the mother how to give it. The antimicrobial susceptibility of local Shigella strains should be monitored regularly and the results used to develop, or modify, national treatment guidelines. Unfortunately, resistance to ampicillin is now widespread and resistance to cotrimoxazole is increasing. Nalidixic acid, formerly used as a "backup" drug to treat resistant shigellosis, is now the drug of choice in some areas, but resistance to it is also appearing. Health facilities should try to stock more than one locally effective antimicrobial for Shigella.
• Antimicrobials that are not effective for shigellosis include: (i) agents to which Shigella are usually resistant, and (ii) those to which Shigella are sensitive in vitro, but which penetrate poorly the intestinal mucosa where invasive Shigella must be killed. Treatment of shigellosis with any of these agents, or an antimicrobial to which resistance has developed, is ineffective.
• Treat and prevent dehydration with oral rehydration therapy. Assess the child for dehydration. If dehydration is detected, it should be corrected at a health facility. Children without evident dehydration should be given increased fluids, preferably including ORS solution, at home.
• Continue to give food and breast milk. Appetite usually improves after1-2 days of effective antimicrobial therapy. Advise the mother to: (i) breastfeed as often and as long as her child wants, (ii) give frequent small meals with familiar, nutritious foods, (iii) encourage her child to eat, and (iv) give an extra meal each day for at least two weeks after diarrhoea stops, to help the child recover any weight lost during the illness.
• Re-evaluate all high-risk children after 2 days. These include children: (i) below 12 months of age, (ii) who present with signs of dehydration, or (iii) who have had measles during the past 6 weeks. Any such child who is not definitely improved (i.e. fewer stools, less blood in the stool, less fever, improved appetite, more active) should be referred to hospital.
• Also advise mothers to bring back any child who does not show definite improvement after 2 days. Stop giving the first anti-microbial and give a second one to which most Shigella in the area are sensitive. If there is still no improvement after 2 days of treatment with the second antimicrobial, it should be stopped and the child referred to hospital or treated empirically for amoebiasis with metronidazole.1 Children who are improving, however, should continue the treatment for 5 days.
• Treat for amoebiasis only when typical trophozoites containing red blood cells are seen in the stool or there is no response to antimicrobial therapy for shigellosis. Metronidazole is the drug of choice for amoebiasis.1 Metronidazole has no efficacy, however, against Shigella or other invasive bacteria and should not be given as routine initial treatment of bloody diarrhoea. It may have serious side-effects and its use makes treatment unnecessarily expensive.

• Ampicillin: Inexpensive, resistant organisms:Most S. dysenteriae type 1; many other Shigella species; dose: 25 mg/kg 4 times a day for 5 days
• Trimethoprim-Sulfamethoxazole (TMP-SMX;also called cotrimoxazole):, Inexpensive, resistant organisms:Many S. dysenteriae type 1; variable among other Shigella species, dose:TMP 5 mg/kg and SMX 25 mg/kg; twice a day for 5 days
• Nalidixic acid: Inexpensive, resistant organisms: Increasing among S. dysenteriae type 1;uncommon among other Shigella species for 5 days, dose:15 mg/kg 4 times a day
• Pivmecillinam: Expensive, resistant organisms: rare among all Shigella species, dose:20 mg/kg 4 times a day for 5 days
• Ceftriaxone:Expensive, resistant organisms: rare among all Shigella species; dose:20 mg/kg twice a day for 5 days

• Metronidazole
• Streptomycin
• Tetracyclines
• Chloramphenicol
• Sulfonamides
• Amoxycillin
• Nitrofurans (e.g. nitrofurantoin, furazolidone)
• Aminoglycosides (e.g. gentamicin, kanamycin)
• First and second generation cephalosporins (e.g., cephalexin, cefamandole)

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Last updated January 21, 1999