Chronic diarrhea overview
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Chronic diarrhea Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Omodamola Aje B.Sc, M.D. [2]
Overview
Chronic diarrhea is a common symptom of many conditions with an estimated prevalence of 5%. Although chronic diarrhea has multiple definitions, a current working definition is the production of loose stools for longer than 4 weeks’ duration. Frequent defecation with normal consistency is termed psuedodiarrhea. There are 3 basic categories of chronic diarrhea: watery, fatty(malabsorption) and inflammatory (with blood and pus). The fundamental pathophysiology of all diarrhea is altered intestinal water and electrolyte transport caused by several factors majorly dependent on the socio-economic status of the population. Treatment is targeted at treating the underlying cause of the diarrhea.
Historical Perspective
The word diarrhea derived from the Greek term "to flow through," is a common manifestation of gastrointestinal disease. Its definition has traditionally been based upon the frequency, volume, and consistency of stools. As a result of various inconsistencies in definition, the American Gastroenterological Association suggests that chronic diarrhea should be defined as a decrease in fecal consistency lasting for four or more weeks.
Classification
Chronic diarrhea may be classified into 3 basic categories: watery, fatty(malabsorption) and inflammatory (with blood and pus). It is important to note that not all chronic diarrhea falls into one category alone. The differential diagnosis for chronic diarrhea is enormous, with a large number of diagnostic tests available that can be used to evaluate these patients. Classifying the patient with chronic diarrhea into a subcategory helps to direct the diagnostic work-up.
Pathophysiology
The fundamental pathophysiology of all diarrhea is incomplete absorption of water from the lumen either because of a reduced rate of net water absorption (related to impaired electrolyte absorption or excessive electrolyte secretion) or because of osmotic retention of water intraluminally.[1] The causes of chronic diarrhea include inflammatory, osmotic, secretory, iatrogenic, motility, and functional diseases. In general, the causes of chronic diarrhea is multifactorial. For example, cholera is caused by secretion and altered motility whereas pseudomembranous colitis is said to be associated with secretion, inflammation, and motility.[2] Thus, diarrhea is a condition of altered intestinal water and electrolyte transport.
Causes
Depending on the socio economic status of the population, chronic diarrhea can be caused by several factors. In a developing nation, the most likely causes of chronic bacteria include; mycobacterial and parasitic infections and less likely to include functional disorders such as malabsorption and inflammatory bowel diseases. In a developed nation however, the most likely cause of diarrhea include; irritable bowel syndrome (IBS), inflammatory bowel disease, malabsorption syndromes (such as lactose intolerance and celiac disease), and chronic infections (particularly in patients who are immunocompromised).
Differentiating Chronic Diarrhea from other Conditions
The differential diagnosis for chronic diarrhea is enormous, with a large number of diagnostic tests available that can be used to evaluate these patients. Classifying the patient with chronic diarrhea into a subcategory helps to direct the diagnostic work-up.
Epidemiology and Demographics
Diarrhea is a common symptom of many different disturbances of gut function. It has been estimated that 3–5% of the population will have chronic diarrhea lasting more than 1 month in any given year.
Risk Factors
The risk factors of chronic diarrhea can be assessed based on the epidemiological associations and the patient characteristics .Some of theses factors can be classified based on travel history, epidemics and outbreaks, diabetic patients, patients with acquired immune deficiency syndrome and whether the patients are institutionalized or hospitalized.
Natural History, Complication and Prognosis
The natural history of chronic diarrhea is watery or bloody or fatty stools for more than 4 weeks duration. Depending on the underlying cause, chronic or severe diarrhea can lead to potentially serious complications some of which include but are not limited to dehydration and malnutrition. The prognosis of chronic diarrhea is good especially when the underlying cause is identified early and treated.
Diagnosis
There are no criteria for the diagnosis of chronic diarrhea. However, in order to make an accurate diagnosis, it is important to be able to take a detailed history, physical exam and mostly from expert opinion and from experience in individual clinical centers. The use of these methods are subject to bias however, a specific diagnosis can be achieved in more than 90% of patients.
History and Symptoms
There are no criteria for the diagnosis of chronic diarrhea. However, in order to make an accurate diagnosis, it is important to be able to take a detailed history, physical exam and mostly from expert opinion and from experience in individual clinical centers. The use of these methods are subject to bias however, a specific diagnosis can be achieved in more than 90% of patients.
Physical Examination
Some of the physical findings of chronic diarrhea are orthostatic hypotension, dehydration, neuropathy, muscle wasting, edema, malnutrition, urticaria pigmentosa, dermatographism, pinch purpura, macroglossia, hyperpigmentation, addison’s disease, migratory necrotizing erythema
Laboratory Findings
The laboratory findings in chronic diarrhea include complete blood count to evaluate for anemia, abnormal white blood cell count, electrolytes, thyroid tests, serological tests for celiac disease and stool analysis for fecal leukocytes, fecal lactoferrin, fecal occult blood.
Electrocardiogram
There are no electrocardiogram findings associated with chronic diarrhea.
Chest X Ray
There are no chest X Ray findings associated with chronic diarrhea.
CT Scan
There are no CT findings associated with chronic diarrhea.
Other Imaging Findings
There are no additional diagnostic findings for chronic diarrhea.
Treatment
Medical Therapy
Antidiarrheal drugs can be broadly defined as agents that minimize the symptoms of diarrhea by improving stool consistency, reducing stool frequency, or reducing stool weight.[3] The treatment of chronic diarrhea is targeted at treating the underlying cause.
Surgery
Surgical intervention is not recommended for the management of chronic diarrhea.
References
- ↑ Sweetser S (2012). "Evaluating the patient with diarrhea: a case-based approach". Mayo Clin Proc. 87 (6): 596–602. doi:10.1016/j.mayocp.2012.02.015. PMC 3538472. PMID 22677080.
- ↑ Kurose I, Pothoulakis C, LaMont JT, Anderson DC, Paulson JC, Miyasaka M; et al. (1994). "Clostridium difficile toxin A-induced microvascular dysfunction. Role of histamine". J Clin Invest. 94 (5): 1919–26. doi:10.1172/JCI117542. PMC 294602. PMID 7962537.
- ↑ Schiller LR (1995). "Review article: anti-diarrhoeal pharmacology and therapeutics". Aliment Pharmacol Ther. 9 (2): 87–106. PMID 7605866.