If you are going to define diarrhea simply, you would say that it is a gastrointestinal symptom characterized by loose watery stool, occurring more frequently than usual. Although some people experience this symptom regularly, they do not know what could cause them, but I will be taking time to explain certain things that could cause a person to have that loose watery stool regularly, that you didn't know could cause it.
While people in developed world might have not experienced cholera first hand, it isn't uncommon for people who live in third word countries, especially those who live in slums and ghettos. It is an acute diarrheal illness and it is a bacteria illness caused by the bacteria Vibrio cholerae which is contracted from contaminated food or water. If left unattended to, it can lead to dehydration and death as the sick person would experience rapid onset of severe watery diarrhea, muscle cramps, vomiting, and dehydration. To treat, it is good to use IV fluid for rehydration, and medical treatment can be used to treat Cholera.
Another cause of diarrhea is the bacteria Escherichia coli (E.coli). While many E.coli strains are harmless, some can cause foodborne illnesses leading to diarrhea, abdominal pain, and vomiting. Amidst all other strains, the strain E.coli 0157:H7 is very dangerous and can release sugar toxin which can lead to complications that can be life-threatening known as Hemolytic Uremic syndrome (HUS) which can lead to low platelet in the blood, kidney failure, as well as different neurological defects.
Giardiasis is a diarrheal disease and it is caused by Giardia lamblia. It is contracted from eating contaminated food or water or from direct contact with persons that have the illness. This illness can come with symptoms such as Diarrhea, Nausea, weight loss, Abdominal pain, and can lead to malnutrition and dehydration.
Salmonella is another bacteria that causes foodborne illnesses that can be contracted from eating contaminated food such as undercooked meat or poultry, eggs, or unpasteurized milk. People who have come down with salmonella infection have symptoms which include fever, abdominal cramps, and diarrhea but in severe cases it can lead to septic shock, and meningitis.
Inflammatory Bowel Disease (IBD) are inflammatory conditions that affect the gastrointestinal tract. These diseases include Crohn's disease, and Ulcerative colitis and they can be accompanied by abdominal pain, blood in the stool, and weight loss, and when untreated, they can lead to bowel obstruction, perforations, and colon cancer risk.
Clostridium difficile can lead to diarrhea as well but this diarrhea can be life threatening and it is common in people who take antibiotics which in turn affects the gut bacteria thereby allowing C.dfficile to take control. This infection leads to watery diarrhea, abdominal pain, and fever, but then can lead to toxic megacolon in severe case which leads to leaky bowel (bowel perforation).
I guess you have been expecting me to mention dysentery since it is pretty common. It is the inflammation of the intestines which can lead to diarrhea and it is often accompanied by blood and mucus in stool. This infection is usually caused by the parasite Entamoeba histolytica or by a bacteria known as Shigella. With dyentery, there are electrolyte inbalance, dehydration, and it can lead to septicemia in severe cases.
Cancers like Colorectal Cancer and Pancreatic Cancer can lead to diarrhea. In the early stages of colorectal cancer, the patient might not experience diarrhea, but as it progresses, it can lead to diarrhea, blood in the stool, abdominal pain and weight loss. Pancreatic cancer on the other hand is an aggressive type of cancer that can go undetected until it is in its late stage. As you would expect, when pancreas isn't released, there will be malabsorbtion of nutrients, leading to diarrhea.
While diarrhea is a self-limiting benign condition, it is important to know that it can symptoms for very serious and life-threatening diseases and conditions. When diarrhea exist for more than 2 days in adult and 24 hours in children, then it should be something of concern. When it is accompanied by blood, high fever, it can be a sign of bacteria or viral infection, or other condition. Cramps or intense abdominal pain should also raise a flag to see a doctor. When the diarrhea comes with vomiting and weight loss, one should visit the hospital immediately.
https://www.nhs.uk/conditions/c-difficile/
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https://www.nhs.uk/conditions/dysentery/
https://www.nhs.uk/conditions/c-difficile/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1199032/
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https://www.fda.gov/food/foodborne-pathogens/salmonella-salmonellosis
https://www.cdc.gov/foodsafety/foodborne-germs.html
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https://www.ncbi.nlm.nih.gov/books/NBK7710/
https://www.cdc.gov/cholera/general/index.html
