Diarrhea

Diarrhea is a common illness caused worldwide. It is caused due to various reasons; infectious organisms such as bacteria, viruses and parasites of intestinal origin. The predominant clinical factor with respect to diarrhea is the onset of vomiting and fever causing extreme dehydration which is fatal and sometimes life threatening.

Bacterial diarrhea: In this case, bacteria such as Salmonella and Shigella and enterogenic E.coli cause damage to the intestinal wall causing more bowel movements and enteric fever. The diagnosis of bacterial diarrhea is done by stool culture and by serological analysis in case of Salmonella induced fever.

Viral Diarrhea: Viral diarrhea is most commonly noticed in children and it is usually self limiting after a period of four to five days. Symptoms include weakness, fever, irritability and sometimes vomiting.

Parasites: Intestinal parasites especially protozoan such as Giardia, Entamoeba and cryptosporidium cause diarrhea. Some are zoonotic on origin and mostly caused by feco-oral route.

Drug Induced: Diarrhea can also be caused because of the administration of certain type drugs such as antibiotics, anticancer and magnesium containing antacids.

Food allergies: Food induced diarrhea is common with those who eat at various places often. Some people are lactose intolerant and consumption of any diary product may induce diarrhea.

Treatment of Diarrhea

Diarrhea can be fatal if untreated. The most common form of treatment is through fluid replacement, rest and consumption of probiotics during the administration of antibiotics. Anti-parasitic drugs and antibiotics are most often prescribed. The WHO recommends ORS solutions in case children and adults as the preliminary step towards treatment and prevention of dehydration.

Stool Culture

Gastroenteritis and bacterial diarrhea are the most common forms of infections that occur both in children and adults. These infections are predominant in tropical regions. The most common etiology for diarrhea is either through parasitic infections or bacterial infections. Both these forms have distinctive clinical characteristics. The identification of the type of disease caused can provide a comprehensive route to differentiate and treat the disease through appropriate anti-parasitic or anti-microbial drugs.

Clinical symptoms

Gastroenteritis or enteric fever identification is characterized by abdominal discomfort, diarrhea and extreme dehydration. In most cases, these kinds of infections occur because of food or water borne contamination. The differential diagnosis of this condition in order to identify the disease is done through additional clinical symptoms, physiological changes and bio-chemical metabolic pathways. One of the most important factors in the identification of bacterial enteric fever is the presence of associated sepsis and spiking fever. In addition to this, in epidemic and highly infectious diseases like Cholera, caused by Vibrio cholera, the cyclic AMP(adenosine mono phosphate) levels are elevated leading to intense dehydration which can be fatal if left unattended.

Diagnosis

In case of bacterial enteric fever or associated diarrheas, stool specimens help understand and identify the type of organism causing the disease. Stool specimens are collected by patients in sterile container and the areas of stool in which blood and mucous are present are used for processing as they are useful portions of the specimen. The obtained media is usually transported by incorporating a transport media to avoid bacterial count decline because of varied PH of the external environment.

Microbiological media such as Selenite feces broth, Mackonkey agar, Salmonella Shigella agar, TCBS medium and Nagglers medium are used in the culture laboratory to identify disease causing organisms such as Salmonella(Typhoid, enteric fever) Shigella( Diarrhea) E.coli 0167or entero - hemorrhagic (Traveler's Diarrhea), Clostridium Botulinum(Food poisoning), Vibrio cholera( Cholera) and Campylobacter.

Apart from these bacteria, stool cultures are also done to identify the presence of enteric viruses such as Rota virus which causes viral gastroenteritis. All organisms isolated are subjected to respective antimicrobial assay to determine the suitable drugs for the respective organism. Careful precautions are taken and clinical details of the patient are recorded by the microbiologist to administer specific drugs for specific organisms. This helps to prescribe medications to specific persons too, such as pregnant and lactating women and children.

Colitis

An inflammation of the inner lining of the colon is colitis. Colitis is an inflammation in the colon and can be associated with diarrhea which could be due to infection, loss of blood supply to the colon, inflammatory bowel disease and invasion of the colon wall with lymphocytic white blood cells or collagen. While the many causes of colitis may be self-limiting and can be treated with diet and observation, nevertheless it is important to find why the inflammation had occurred as there can be more serious causes.

In case of ulcerative colitis, the exact cause remains unknown and previous diet and stress are suspected. However, doctors opine that these causes may aggravate but not cause ulcerative colitis. One possible reason could be immune system malfunction. An abnormal immune response can cause the immune system to attack the cells in the digestive tract and thereby cause malfunction. Heredity can also play a role in ulcerative colitis and it is more common in those who have a family history of the disease.

Infectious Colitis

The most common bacteria that can cause colitis are Campylobacter, Shigella, E. coli, Yersinia, and Salmonella. Most of the time infections occur as the patient has eaten contaminated food. Hence the symptoms of diarrhea with or without blood, abdominal cramps, dehydration from loss of water.

Yet another bacteria that can cause colitis is Clostridium difficile. While C.diff which is found in the colon of a healthy individual co-exists with other normal bacteria, when antibiotics are prescribed, the susceptible bacteria in the colon can be destroyed and this allows clostridia to grow unchecked, and thereby cause colitis. Unfortunately, these bacteria are also found in many surfaces in the hospitals, and hence can be contagious from person to person.

In fact, worldwide the most common parasite infection that can cause colitis is Entamoeba histolytica. This is acquired by drinking infected water and can also be passed on from one to another because of poor hygienic and sanitation conditions.

Microscopic colitis can infiltrate the wall of the colon, as a result of inflammation and this is an uncommon illness and could be an auto-immune disease. In this case, the diarrhea is watery and no blood is present in the feces. In infants younger than a year, colitis is often due to allergies to cow and soy milk. Allergic colitis can also be seen in breast fed babies, where the mother drinks cow's milk and passes that protein into their breast milk.

Ulcerative Colitis can be severe depending upon its location, reading from the signs and symptoms. Depending upon which part of the colon is inflamed it could cause diarrhea, abdominal cramps, rectal pain, rectal bleeding, urgency to defecate, inability to defecate despite urgency, weight loss and fatigue, fever and failure to grow in children.

Diagnosis of Colitis

To confirm the diagnosis, the doctor may prescribe the following tests and procedures:

• Blood tests for anemia and to check signs of infection.
  
• A stool sample to help rule out other disorders such as infections caused by bacteria, viruses and parasites.
  
• Colonoscopy to view the entire colon. The doctor can take a small biopsy during the procedure for laboratory analysis. A tissue sample can help confirm the diagnosis.
  
• Flexible Sigmoidoscopy to examine the last portion of the colon and if it is severely inflamed, the doctor can perform this test instead of colonoscopy.
  
• X rays of abdominal area to rule out serious complications, such as a perforated colon.

Treatment

There are several categories of drugs depending upon the severity of the condition. The drugs may work well for some but not for all. Also, drugs can cause serious side effects which can far overweigh the benefits of the treatment.

Anti-inflammatory drugs are the first step in the treatment of inflammatory bowel disease. Aminosalicylates, and Corticosteroids and immune system suppressors are prescribed. These are given orally, intravenously or by enema depending upon the location that is affected. Corticosteroids can have several side effects including puffy face, excessive facial hair, insomnia and hyperactivity and more serious ones such as hypertension, diabetes, osteoporosis, bone fractures and cataracts. These are not usually prescribed for long term.

While immune system suppressors can reduce inflammation, they do so by suppressing the immune system and therefore start the process of inflammation. A combination of drugs works better is most cases. Other medications include antibiotics, anti-diarrheal medications, pain relievers and iron supplements.

Surgery

Surgery can eliminate ulcerative colitis by removing the entire colon and rectum. This procedure called ileoanal anastomosis eliminates the need to wear a bag to collect the stool. The surgeon constructs a pouch from the end of the small intestine. This pouch is then attached directly to the anus allowing expulsion of waste relatively normally. When a pouch is not possible, the surgeon creates a permanent opening in the abdomen, through which the stool is passed for collection into an attached bag.

Complications of colitis

It is recommended to have more frequent screening for colon cancer because of increased risk although it will depend on the location and duration of the disease. Some complications that can occur:

• Severe bleeding
  
• Perforated colon
  
• Severe dehydration
  
• Liver disease
  
• Osteoporosis
  
• Inflammation of joints, skin, joints of eyes, and sores in the lining of mouth
  
• Increased risk of colon cancer
  
• Swelling colon
  
• Increased blood clots in veins and arteries.