Diarrhea is too frequent, often too precipitate passage of poorly formed stools. It has a high risk of causing morbidity and mortality. More than 5 million children under the age of 5 years die every year due to diarrhea. Diarrhea is not a disease by itself, it is mostly a symptom of another disease.

Causes of diarrhea include diet (eating something that is difficult to digest), genetic disorder (lactase deficiency), infection (bacterial, viral, fungal, parasitic), toxic, drug-induced and stress (IBS).

Relevant pathophysiology can be described under one of the following scenarios:

}  Osmotic Load within the intestine resulting in retention of water within the lumen e.g, malabsorption

}  Excessive secretion of electrolytes and water into the intestinal lumen e.g, ETEC, Cholera

}  Exudation of the fluid and protein from the intestinal mucosa e.g, Ulcerative colitis

}  Altered intestinal motility resulting in rapid transit through the colon e.g, IBS, DM

Rational therapy includes treatment of cause and instituting specific therapy. Therapeutic measures may be grouped into treatment of fluid depletion, shock and acidosis, maintenance of nutrition and drug therapy as required according to the severity and nature of diarrhea.

Basic investigations can include blood levels of Na, K, urea, creatinine, pH/ Bicarbonate and urinalysis. Specific investigations include stool microscopy and culture, serodiagnosis, abdominal imaging, endoscopy and histology.

There are four main approaches to the treatment of infectious diarrhoea.

·       Supportive therapy—fluid and electrolyte replacement.

·       Anti-diarrhoeal symptomatic treatment to reduce stool frequency and any other symptoms such as abdominal pain.

·       Anti-secretory drug therapy aimed at reducing faecal losses.

·       Specific therapy such as antimicrobial chemotherapy to reduce duration and severity of the illness.

Oral rehydration solution should be isotonic or somewhat hypotonic, i.e. total osmolarity 200–310 mOsm/L (diarrhoea fluids are approximately isotonic with plasma, which is ~290 mOsm/L). The molar ratio of glucose should be equal to or somewhat higher than Na+ (excess glucose will be utilized in absorbing Na+ present in the intestinal secretions), but not exceed 110 mM. Enough K+ (15–25 mM) and bicarbonate/ citrate (8–12 mM) should be provided to make up the losses in stool.

Constituents of ORS
NaCl	2.6g	Na+	-75mM
KCl	1.5g	K+	20 mM
Trisod. Citrate	2.9g	Cl-	65 mM
Glucose	13.5 g	Citrate	10 mM
Water	1 L	Glucose	75 mM
Total osmolarity 245mOsm/L

 

Patients are encouraged to drink ORS at ½ to 1 hourly intervals, initially 5 – 7.5%. Amount of intake of ORS depends on thirst. Subsequently it may be taken according to demand and cover the rate of loss of fluids in stools. Once reconstituted, use or dispose off the remaining ORS in 24 hours. In most cases, the only required treatment is ORS. Rehydration can be done orally or i.v. ORS for all ages and all types of diarrhea. Continue breast feeding, normal diet and consume energy dense foods. Risk of hyponatremia not significant in any type of diarrhea – thus low osmolarity ORS (245 mOsm/L) recommended by WHO.

Acceptable home available fluids include cocnut water, fresh fruit juice without sugar, plain water, plain buttermilk, milk in moderation, thin lentils. Coffee, aerated drinks, too much milk and canned juices with sugar should be avoided. Fisher and Walker recommendations to reduce mortality due to diarhea include breastfeeding, Vitamin A supplementation, hand washing with soap, improved sanitation, safe drinking water, rotavirus vaccination, treatment with ORS and antibiotics for dysentery

IV rehydration, if needed, may be given in the form of Ringer Lactate or normal saline.

In invasive diarhea with small volume stools, mucous/blood, abdominal cramps, urgency, fever but no vomiting. In such cases, antibiotics are needed. In non-invasive, watery diarhea with no mucous/blood, dehydrating, vomiting, periumbilical cramps but little or no fever, ORS is needed. Ask A Doctor, if one needs further management with medicines.

 

 

Written by Dr Vaishalee Punj