| Fact | Explanation |
|---|---|
| Passage of three or more watery stools per day. [3] | Basic pathology in the infectious diarrhoea is to increase intestinal secretion of fluid and electrolytes,mainly in the small intestine and decrease absorption of fluid, electrolytes, in the small and large intestine. Secretory enterotoxins from the infectious organism may activate the secretory processes. eg:- Zonula occludens toxin, produced by V cholerae O1 acts on the small intestine. There are evidence to suggest that the neuronal pathways improve the effects of enterotoxins. [2] Impaired epithelial transport processes, osmotic diarrhoea, and impaired water and sodium reabsorption by the colon are some mechanisms involved in the reduced absorption. Viral causes of diarrhoea include rotavirus, adenovirus, and corona viruses. Bacteria causes of diarrhoea include Vibrio cholerae, Escherichia coli, Campylobacter Jejuni [4] , Salmonella and Shigella species. Parasitic causes of diarrhoea include Giardia, Entamoeba, Cryptosporidium and the helminthes (Strongyloides, Schistosoma) Rotavirus , campylobacter, salmonella are the common causes for the watery diarrhoea. Cholera causes massive persistent watery diarrhea that looks like rice-water diarrhea. [5] |
| Fever | Fever accompanies the diarrhoea. [3] Patients can develop acute fever after the exposure. Invasion of epithelial cells by bacteria and viruses lead to the release of cytokines during inflammation. These pyrogens responsible for the fever. |
| Vomiting, body weakness, fatigue | Can be associated with diarrhoea. [3] |
| Severe thirst and drowsiness | Due to the dehydration. [1] |
| Seizures | Cholera infection can cause seizures. [10] |
| Exposure to contaminated materials | Eating from restaurants, caterers, bakeries increase the risk of getting infections. Raw meat, poultry and seafood may be contaminated with feces while processing. Eggs produced by the infected animals may be infected with salmonella. Lack of proper hand washing practice is a major contributing factor. [11] |
| History of immunodeficiency: Cancer and cancer chemotherapy, Undernutrition, congenital immunodeficiency, HIV/AIDS | These groups are vulnerable to recurrent diarrhoea due to the defects in the immunity. [2] |
| Rectal bleeding, constipation, sense of incomplete evacuation of the rectum and pain during defecation(tenesmus), poor appetite | Inflammatory bowel disease (Crohn's disease and ulcerative colitis) characterized by persistent watery diarrhea. Crohn’s disease affects terminal ileum and colon, ulcerative colitis affects mainly the colon. [5] Inflammatory mucosal lesions in the intestines produce abdominal pain, discomfort and bleeding per rectum. |
| Weight loss | Crohn's disease patients usually have a longterm history of diarrhoea and suffering from malnutrition. This can also lead to weight loss. [7] |
| Joint pain | A feature of inflammatory bowel disease. [7] |
| Night sweats | A feature of inflammatory bowel disease. [6] |
| Abdominal discomfort or pain improves with defecation | This can be a feature of Irritable bowel syndrome that can presents with watery diarrhoea. In irritable bowel syndrome, there is abdominal pain that improves with defecation, may be related to stressful situations and there are no other pathologies that explains the symptoms. [8] |
| Passage of stools following dairy food ingestion | Lactose is a disaccharide presents in the milk. Lactase breaks down lactose into absorbable sugars. When there is a deficiency of lactase activity, maldigestion of lactose occurs. Lactase deficiency may be due to primary hypolactasia or secondary to other causes such as celiac disease, infectious enteritis, or Crohn’s disease. Milk and products made with milk will produce diarrhoea in infants. [9] |
| History of drug use; Tacrine hydrochloride, donepazil chemotherapy [12] , antibiotics, non steroidal anti inflammatory drugs, penicillamine misoprostol, bisacodyl, urodeoxycolic acid, digoxin and colchicine, magnesium containing antacids, lactulose and acarbose | Drugs can cause diarrhoea by several mechanisms. [12] Some of them are parasympathetic stimulation, increase intestinal motility and produces diarrhoea, causes direct damage to the intestinal mucosa, villous atrophy and malabsorption and diarrhoea, secretory diarrhoea, decrease the sodium potassium ATPase activity, and osmotic diarrhoea. |
| Fact | Explanation |
|---|---|
| Febrile | Acute diarrhoea can present with acute fever. Chronic diarrhoeal conditions such as Crohn's disease and ulcerative colitis can also presents with fever. [4] |
| Sunken anterior fontanelle in infants, reduced skin turgor, absence of tears, and reduced urine flow [1] | These are found in dehydrated patients. Assessment of the hydration status is important in the fluid management. |
| Hypotension | Systolic blood pressure can get reduced with dehydration. [1] |
| Altered mental state | Due to severe dehydration. [5] |
| Wasting | This is due to inflammatory bowel disease. Crohn's disease patients will have long term loss of proteins as chronic diarrhoea leading to malnutrition. They also have impaired absorption of nutrition due to the intestinal lesions. [2] |
| Mouth ulcers | Can be seen in ulcerative colitis. [6] |
| Joint and bone tenderness | Patients with crohn's disease may have arthritis as an extraintestinal manifestation. They also can develop spinal lesions: spondylitis and complains of back pain. [3] |
| Red eye | Uveitis is an extraintestinal manifestation of inflammatory bowel disease. [4] |
| Perianal excoriation and fistula | Perianal excoriation is seen in lactose intolerance. Fistulae are seen in crohn's disease. [3] |
| Fact | Explanation |
|---|---|
| Acute (viral) gastroenteritis | This is the most common cause of watery diarrhoea. Viral causes of diarrhoea include rotavirus, adenovirus, and corona viruses. Bacteria causes of diarrhoea include Vibrio cholerae, Escherichia coli, Campylobacter Jejuni, Salmonella and Shigella species. Parasitic causes of diarrhoea include Giardia, Entamoeba, Cryptosporidium and the helminthes (Strongyloides, Schistosoma) Rotavirus , campylobacter, salmonella are the common causes for the watery diarrhoea. [3] Shigella, salmonella and enterohemorrhagic E. coli (EHEC) causes bloody diarrhea, [4] but during the initial stages of the disease they can present with watery diarrhoea. |
| Inflammatory bowel disease | Crohn’s disease causes inflammation in the lining of the gastrointestinal tract. It often affects the ileum and colon. There is scarring and swelling of the intestinal mucosa. In Crohn disease, there can be a damage to distal ileum that can lead to bile acid malabsorption, result in diarrhea. Also there can be enterocolic fistula causing diarrhoea. ln ulcerative colitis there can be inflammatory mediators that are responsible for the colonic secretion. [2] |
| Pancreatic or adrenal tumours | Serum Vasoactive Intestinal Polypeptide (VIP) in the intestine is responsible for the increased electrolyte and bicarbonate secretion by activating adenylate cyclase and cyclic AMP in intestinal cells [2] and decreased absorption leading to the symptoms of watery diarrhoea, hypokalaemia and achlorhydria. [1] This elevated serum vasoactive intestinal polypeptide (VIP) is found either in pancreatic or adrenal tumours. Resection of the tumour is the available management option. [1] |
| Drugs | Tacrine hydrochloride and donepezil are cholinergic drugs that causes parasympathetic stimulation, increase intestinal motility and produces diarrhoea, Chemotherapy [6] , antibiotics, non steroidal anti inflammatory drugs and penicillamine causes direct damage to the intestinal mucosa, villous atrophy and malabsorption and diarrhoea. Misoprostol, bisacodyl and ursodeoxycholic acid cause secretory diarrhoea. Digoxin and colchicine decrease the sodium potassium ATPase activity and result in diarrhoea. Magnesium containing antacids , lactulose and acarbose result in osmotic diarrhoea. [7] |
| Traveller's diarrhoea | Acute diarrhea can be due to associated with international travel which is commonly caused by enterotoxigenic Escherichia coli, enteroaggregative E. coli, or noroviruses. This can presents either as acute watery diarrhea or febrile and dysenteric diarrhea as in shigella infection. [5] Rifaximin, trimethoprim-sulfamethoxazole, fluoroquinolone, or azithromycin will be the treatment options available for the diarrhoeal management in these patients. Chemoprophylaxis with rifaximin is important to prevent the traveller's diarrhea. |
| Fact | Explanation |
|---|---|
| Stool microscopy and culture | Stool samples are examined under the light microscope for parasites,cysts and spores such as Entamoeba histolytica, Giardia intestinalis, Cryptosporidium parvum, and Cyclospora cayetanensis and cysts and spores. [2] |
| Enzyme Linked Immuno Sorbent Assay (ELISA) | Faecal antigen ELISAs is now used to detect the rotavirus infection. [2] |
| Serum Vasoactive Intestinal Polypeptide (VIP) levels | VIP in the intestine is responsible for the increased electrolyte and bicarbonate secretion and decreased absorption leading to the symptoms of watery diarrhoea, hypokalaemia and achlorhydria. [1] This elevated VIP is due to either pancreatic or adrenal tumour. |
| Lactose tolerance tests | Used to confirm lactose intolerance. [3] A sample of blood is taken after fasting, and another sample will be taken after 2 hours of lactose load. Then the rise in the blood sugar in the second sample is compared as absence of significant increase in the blood sugar in that sample indicates the lactose intolerance. |
| Fact | Explanation |
|---|---|
| Full blood count | As the patient is presenting with the fever, it is important to exclude the other conditions such as viral infections that can present with increased lymphocytes in the blood (lymphocytosis) and reduced platelets count. Pack cell volume may be increased in dehydration. Anemia is present in patients with inflammatory bowel disease, manifested as reduction of level of haemoglobin. Elevated white blood cell count (leucocytosis) is also present in these patients. Neutropenia is seen in patients with immunodeficiency and chemotherapy induced diarrhoea. [2] |
| Serum electrolytes | There can be hypokalaemia, [1] hytponatraemia and hypochloraemia due to electrolyte loss. |
| Fact | Explanation |
|---|---|
| Serum electrolytes | As there is loss of electrolytes during diarrhoea, it is important to monitor them to assess response to therapy. [1] Usually in diarrhoeal patients there is reduced potassium, sodium and chloride due to intestinal loss. These should be normalized with the rehydration . |
| Fact | Explanation |
|---|---|
| Serum electrolytes | Electrolyte depletion is a result of diarrhoea, which can even result in severe imbalances especially in potassium. [1] |
| Acid base balance | Acidosis is a complication due to the loss of bicarbonates. It is a metabolic type of acidosis. [1] |
| Urinary catecholamines and catechol metabolites | Analysis of urine in suspected cases of vasoactive intestinal polypeptide secreting tumours will reveal the presence of abnormal amounts of catecholamines and catechol metabolites. [2] |
| Colonoscopy | Used in suspected patients with inflammatory bowel disease. [3] |
| Fact | Explanation |
|---|---|
| Prevention | Important measures to prevent diarrhoea are using safe drinking-water, improving the sanitation, good personal and food hygiene and health education about prevention of infections and good sanitation. Good hand washing practices are vital in preventing diarrhoeal episodes. [1] |
| Exclusive breastfeeding for the first six months of life | These children are less likely to expose to the contaminated foods or fluids. [1] It is shown that breast feeding reduces the child morbidity and mortality in diarrhoeal episodes. |
| Antimotility agents | Antimotility agents such as loperamide and a diphenoxylate-atropine combination are used in diarrhea as it increase the intestinal transit time and give more time for absorption of fluid and electrolytes, reduce the faecal losses. Loperamide also has an antisecretory activity. [2] |
| Antisecretory drugs | Studies are done on these drugs that will directly inhibit secretory processes within the enterocyte. These are used in acute secretory diarrhoea such as cholera and traveller's diarrhoea. eg:- Zaldaride maleate, a calmodulin inhibitor, which targets the intracellular signalling mechanisms especially calcium and the calcium binding protein calmodulin, enkephalins and enkephalinase inhibitors. [2] |
| Probiotics | Probiotics are live microbes that provides same action as normal human gut microflora. Some of them are lactobacillus , bifidobacterium and streptococcus. These will reduce the incidence of repetitive diarrhoea in children. [2] |
| Zinc supplements | Zinc supplementation reduces the frequency, severity of diarrhoeal episodes and reduces the risk of recurrent diarrhea attacks. It also enhances efficacy of oral cholera vaccine. [3] |
| Management of lactose Intolerance | Temporarily avoiding milk and dairy products is important. [4] |
| Fact | Explanation |
|---|---|
| Rehydration | Diarrhea may require oral rehydration, and if severe even intravenous fluids. Prevention and timely treatment of dehydration helps to prevent deaths due to diarrhoea. [2] Oral rehydration solution with total osmolarity 311 mmol/l is the current recommendation by the world health organization. As there is loss of fluid and electrolytes during the diarrhoea there can be dehydration, hyponatraemia, hypokalaemia, and metabolic acidosis(due to bicarbonate loss). The glucose-sodium co-transporter is preserved in diarrhoeal diseases. Therefore if external solution can provides these electrolytes it can replace the loss. ORS contains sodium, potassium, chloride, citrate and glucose anhydrous in appropriate amounts. During the management of mild to moderate dehydration, rehydration requires 50-100ml/kg over 3-4 hours. Usually around 50 ml of ORS per each stool is required for the replacement. If there are features of overhydration such as swelling of eyelids, ORS should be temporarily stopped. Breast feeding should be continued during the episode. Severe cases need intravenous fluid replacement with 0.9% normal saline/ringer's lactate. |
| Antibiotic therapy | Unless the illness is severe or due to cholera. usually antibiotics are not indicated in acute watery diarrhea as it can cause adverse effects such as antibiotic resistance and antibiotic side effects. [2] Cholera is managed with tetracycline for three days. Doxycycline, trimethoprim-sulphamethoxazole, norfloxacin, and ciprofloxacin also effective in cholera. Traveller’s diarrhea is treated with broad spectrum antibiotics as it is due to the bacterial enteropathogens. Drug of choice will be quinolone for 3–5 days. trimethoprim-sulfamethoxazole and ampicillin can also be used, but the resistance is a problem. [2] |
| Management of inflammatory bowel disease | Current treatment for the inflammatory bowel disease includes anti-inflammatory agents such as corticosteroids, immunomodulators, sulfasalazine, azathioprine, biologic agents and surgical options including colectomy. [2] |