involves
Diarrhea or vomitting, with noninflammatory
Infection of the
Upper Small Bowel , or inflammatory infection of the
Colon , both part of the
Gastrointestinal Tract .
Sleisenger & Fordtran's Gastrointestinal and Liver Disease 7th edition, 2-Volume Set, By Mark Feldman, MD, Chair of Internal Medicine, Presbyterian Hospital of Dallas, Clinical Professor of Internal Medicine, University of Texas Southwestern Medical School of Dallas, Dallas, TX; Lawrence S. Friedman, MD, Professor of Medicine, Gastroinstestinal Unit, Massachusetts General Hospital, Boston, MA; and Marvin H. Sleisenger, MD, Distinguished Physician, Department of Veterans Affairs Medical Center, San Francisco, CA, ISBN 0721689736 · Hardback · 2688 Pages · 850 Illustrations, Saunders · Published July 2002
Mandell's Principles and Practices of Infection Diseases 6th Edition (2004) by Gerald L. Mandell MD, MACP, John E. Bennett MD, Raphael Dolin MD, ISBN 0443066434 · Hardback · 4016 Pages Churchill Livingstone
Harrison's Principles of Internal Medicine 16th Edtion, The , ISBN 0192629220
Usually this is caused by an infection, but this is not always the case. It usually is of acute onset, normally lasting less than 10 days and self-limiting. Sometimes it is referred to simply as 'gastro'. It is often called the or '''gastric flu''' even though it is not related to
Influenza .
If the inflammation is limited to the stomach, the term
Gastritis is used, and if the small bowel alone is affected it is
Enteritis .
There are several causes of gastroenteritis, most of which infective (
Virus ,
Bacterium ,
Parasite ). Young children and elderly people are most at risk for this condition to be severe or to develop complications.
See Also: Traveler's diarrhea
Travellers' diarrhea is seen in people travelling from developed to less developed countries. The pathogens commonly responsible are C. jejuni which is seen in a significant proportion of cases, particularly during cooler seasons, various forms of E. coli, particularly ETEC. But also viruses, Shigella, Salmonella, Giardia, Cryptosporidium, and Cyclospora spp. are seen, though these are less common. Generally the disease is selflimiting, lasting 1 to 5 days.
The most common viral causes of (AGE) in children <5 years of age in both
Developed Countries as well as developing countries are
Rotavirus Group A (up to 50% of the cases),
Noroviruses (the most common cause of outbreaks of AGE in all age groups),
Adenoviruses Type 40 and
41 ,
Astrovirus , and
Sapovirus .
Virusses commonly seen in gastroenteritis are: rotaviruses; enteric adenoviruses; small, round structured viruses (SRSVs) and classic human caliciviruses; and astroviruses. Not regularly seen in infectious diarrhoea, but present in the gastrointestinal tract, are enteroviruses, reoviruses, non-group F adenoviruses, toroviruses, coronaviruses, and parvo-viruses. In case of
Immunocompromised patients (i.e.
Human Immunodeficiency Virus (HIV) infected, using
Corticosteroid s or recently treated with
Chemotherapy ) one can find
Herpes Simplex Virus (HSV),
Cytomegalovirus (CMV), and
Picobirnaviruses .
This is less common in developed countries. ''
Campylobacter Jejuni '' is responsible for 5-10% of cases, whereas ''
Salmonella '' species, ''
Shigella '' species, and various pathogenic types of ''
Escherichia Coli '' account for a small percentage.
In the
Developing World enterotoxigenic, enteropathogenic and enteroinvasive ''
E. Coli '' are important due to the sheer number of cases, whereas ''
Shigella '' causes debilitating illness and has increasing resistance against cheap and readily available
Antibiotic s.
Cholera , caused by ''
Vibrio Cholerae '' is another important cause of acute diarrhoeal illness and subsequent death in the developing world.
Usually bacterial
Food Poisoning is caused by Bacillus cereus, Salmonella spp., C. botulinum, Shigella spp., toxigenic E. coli (ETEC and EHEC), Clostridium perfringens, Staphylococcus aureus, Vibrio spp. (including V. cholerae and V. parahaemolyticus), and certain species of Campylobacter, Yersinia, Listeria, and Aeromonas.
Most frequently dysenteric illness is associated with
Entamoeba Histolytica , but Balantidium coli,
Schistosoma Mansoni , S. japonicum,
Trichuris Trichiura ,
Hookworm s, and
Trichinella Spiralis too can be the causative agent.
Outbreaks of ''
Giardia Lamblia '' can cause dehydrating diarrhoea in infants, and ''
Cryptosporidium '' is known to cause 1-4% of cases of acute diarrhoea in hospitalised infants.
An important cause to remember is
Antibiotics Associated Colitis or pseudomembranous colitis. Therapy with antibiotics (i.e.
Cephalosporin s and
Clindamycin ) or chemotherapeutics (i.e.
Methotrexate ) can result in this condition.
Clostridium Difficile is inhibited by the normal intestinal flora, antibiotics disturb that balance and C. difficile can multiply. Cytotoxin A, produced by C. difficile, damages the colonic mucosa.
Some forms of chemotherapy (i.e.
Methotrexate ,
Irinotecan ), through damage to the mucosa (
Mucositis ), can cause
Stomatitis ,
Oesophagitis ,
Gastritis and
Enteritis .
Holland-Frei Cancer Medicine By Donald W. Kufe, MD, Harvard Medical School, Boston, MA, USA; Raphael E. Pollock, MD, MD Anderson Hospital, University of Texas, Houston, TX, USA; Ralph R. Weichselbaum, MD, Professor and Chairman, Department of Radiation Oncology, Pritzker School of Medicine, Michael Reese/University of Chicago Center for Radiation Therapy, Chicago, IL, USA; Robert C. Bast, Jr., M.D. Anderson Cancer Center, Houston, TX, USA; Ted S. Gansler, MD, MBA; James F. Holland, MD, ScD(hc), Mount Sinai Medical Center, New York, NY, USA; and Emil Frei, III, Harvard Medical School, Boston, MA, USA, 6th edition, 2-Volume Set with CD-ROM, ISBN 1550092138 · Hardback · 2900 Pages · 500 Illustrations BC Decker · Published July 2003
Globally,
Diarrhea caused 4.6 million deaths in children in 1980 alone, most of these in the
Developing World . The
Harrison's Principles Of Internal Medicine estimates the current total figure to be 2.4 to 2.9 million per year. This number has now come down significantly to approximately 1.5 million deaths annually, largely due to global introduction of proper
Oral Rehydration Therapy Victora et al 2000
The incidence in the
Developed Countries is as high as 1-2.5 cases per child per year and a major cause of hospitalisation in this age group.
Age, living conditions, hygiene and cultural habits are important factors. Another factor is the location. Aetiological agents vary depending on the climate. Furthermore, most cases of gastroenteritis are seen during the winter in temperate climates and during summer in the tropics.
The main symptoms include poor feeding in infants, vomiting and fever, usually rapidly followed by diarrhea. Viral diarrhea usually causes frequent watery stools, whereas blood stained diarrhoea may be indicative of bacterial colitis.
The child with gastroenteritis may be
Lethargic and have signs of dehydration, dry mucous membranes,
Tachycardia , reduced skin turgor, sunken fontanelles and sunken eye balls, poor perfusion and ultimately
Shock .
It is important to consider infectious gastroenteritis as a
Diagnosis Per Exclusionem . A few loose stools and vomiting may be the result of systemic
Infection such as
Pneumonia ,
Septicaemia ,
Urinary Tract Infection and even
Meningitis . Surgical conditions like
Appendicitis ,
Intussusception and, rarely, even
Hirschsprung's Disease may mislead the clinician.
Non-infectious causes to consider are poisoning with heavy metals (i.e.
Arsenic ,
Cadmium ), seafood (i.e.
Ciguatera ,
Scombroid , toxic encephalopathic shellfish poisoning) or mushrooms (i.e.
Amanita Phalloides ). Secretory tumours (i.e.
Carcinoid , medullary tumour of the thyroid, vasoactive intestinal peptide-secreting adenomas) and endocrine disorders (i.e.
Thyrotoxicosis and
Addison's Disease ) are disorders that can cause diarrhoea. Also pancreatic insufficiency, short-gut syndrome, Whipple's disease, coeliac disease and laxative abuse should be excluded as possibility.
The principal treatment of diarrhoeal illness in both children and adults is
Rehydration , i.e. replenishment of water lost in the stools. Depending on the degree of dehydration, this can be done orally with (
Oral Rehydration Solutions (ORS)), commercial or home-made rehydration fluids, or through
Intravenous delivery. Symptoms may exhibit themselves for up to 6 days. Bowel movements will return to normal within a week after that.
Because of the stomach's fragility due to the disease, rehydration through the drinking of fluids must be slow and spaced out as to not overwhelm the stomach and cause further nausea and vomiting. Doctors recommend that one take slow sips every few minutes, and if vomiting still occurs, it's best to refrain from any drinking or eating for the next half hour.
When the symptoms are severe one usually starts empirical antimicrobial therapy, i.e.
Fluoroquinolone . Pseudomembranous colitis is treated by discontinuing the causative agent and starting with
Metronidazole .
Loperamide is an
Opioid analogue commonly used for symptomatic treatment of diarrhoea. It slows down gut motility, but does not cross the mature
Blood-brain Barrier to cause the central nervous effect of other opioids. In too high doses, loperamide may cause constipation and significant slowing down of passage of feces, but an appropriate single dose will not slow down the duration of the disease. (Wingate et al, 2001) Although
Antimotility Agent s have the risk of exacerbating the condition, this fear is not supported by clinical experience according to
Sleisenger & Fordtran's Gastrointestinal And Liver Disease and the
Oxford Textbook Of Medicine . Nevertheless,
Harrison's Principles Of Internal Medicine discourages the use of antiperistaltic agents and opiates in febrile dysentery, since they may mask, or exacerbate the symptoms. All these
Textbook s agree that in severe colitis antimotility drugs should not be used.
Loperamide prevents the body from flushing toxins from the gut, and should not be used when an active fever is present or there is a suspicion that the diarrhea is associated with organisms that can penetrate the intestinal walls, such as or
Salmonella .
Loperamide is also not recommended in children, especially in children younger than 2 years of age, as it may cause systemic toxicity due to an immature blood brain barrier, and oral rehydration therapy remains the main stay treatment for children.
Bismuth Subsalicylate (BSS), an insoluble complex of trivalent bismuth and salicylate, is another drug that can be used in mild-moderate cases.
Combining an antimicrobial drug and an antimotility drug, seems to be effective more rapidly.
Antibiotics are of little or no use, unless persistent symptomatic colonisation (as seen in ''
Giardia Lamblia '' infestations) or
Septicaemia is present.
Dehydration is the most concerning complication of the
Diarrhea caused by gastroenteritis and needs prompt rectification by a clinician if severe.
Febrile Convulsion s are not uncommon in children, especially with
Rotavirus infections.
Sugar
Malabsorption is the most common complication, especially in infants. This may result in reappearance of
Diarrhea once
Milk , and hence the sugar
Lactose , is reintroduced into the diet.
- Victora, C. G., Bryce, J., Fontaine, O., & Monasch, R. 2000, 'Reducing deaths from diarrhoea through oral rehydration therapy', ''Bulletin of The World Health Organization'', vol. 78, no. 10, pp. 1246-1255.
- Wingate D. et al. 2001. 'Guidelines for adults on self-medication for the treatment of acute diarrhoea', ''Alimentary Pharmacology & Therapeutics'', vol. 15, no. 6, pp. 773-782.
