Technically, our intestines are not ‘inside’ us. Think of the classic tube within a tube, and you will see that our gastrointestinal tract (food pipe, stomach, intestines) is actually open to the outside world from both ends. Small wonder then, that germs of all sorts can enter almost at will, to either peacefully co-exist, or wreak havoc. Diarrhoea is caused by infectious agents (i.e., bacteria, viruses, parasites) or non-infectious entities (think inflammatory bowel diseases, irritable bowel syndrome subtypes, food allergies and intolerances, hormonal influences, medication side effects and, rarely, cancers). Everyone gets diarrhoea. So when should we worry? Here is a list (an incomplete one, because how could everything be covered in one blog, right?) of red flag symptoms that warrants immediate investigation and treatment: Massive, explosive diarrhoea. Trust me, you’ll know when you have this. Diarrhoea if this sort can dehydrate you to dangerous levels before you can say king coconut water. Indications of serious dehydration include the following: rapid heart rate, low blood pressure (or a drop from your usual blood pressure), weakness, dizziness, confusion, and decreased urine output. Diarrhoea mixed with blood (i.e., dysentery). This needs prompt investigation and treatment. Diarrhoea lasting more than 3-4 days. Always good to investigate. Of note, parasitic infections typically cause long-standing diarrhoea (think days to weeks to months), although aggressive parasites such as Entamoeba histolytica (“amoeba”) can cause acute illness often indistinguishable from bacterial culprits.


Diarrhoea with high fever. This typically indicates an invasive infection or inflammatory process.

Diarrhoea with unintentional weight loss, or other worrisome symptoms.


Diarrhoea with any red flags, or diarrhoea that just doesn’t feel right, is a good enough reason to contact your friendly neighbourhood tropical medicine specialist for those visiting or living in Southeast Asia. So we can’t run from the runs, but we can do a lot to reduce how often we get the runs. Do these: Pay attention to food and water safety. I’m not going to preach about avoiding street food (mostly because I love street food) but expect to get the runs if you are a street food fanatic, and choose your battles wisely.

Boiling water is an effective means to removing most (but not all) germs. A vigorous boil for one minute is all you need to kill most of the culprits. Note, certain parasites are removed only from fine filtration. See interesting filter information here. Avoid swimming in contaminated water (if you can connect the dots between the water you are about to dive into and the village cesspit, not a good idea). Be cautious with ice, which may be made from untreated water. Listeria, E.coli and Salmonella species can survive on ice cubes. Brushing teeth with contaminated water is also a potential breech. Remember, bacteria like certain Shigella species need only 10 microscopic critters to infect you. That number of germs can tag along on a single hair of a house fly’s leg. Keep your hands clean. Wash with soap and water like this. Soap and water is preferred over the use of hand sanitizer. However, where soap and water may not be readily accessible, hand sanitizers offer reasonable protection.

How do we treat diarrhoea? Infectious diarrhoea, for the most part, will sort itself out without any need for medications. Even some of the common bacterial causes will be sorted out in three, perhaps four days. However, certain types of infectious diarrhoea will require immediate and specific treatment. An experienced doctor will know when to treat, and when to leave well alone.

Rehydration is very important in the treatment of diarrhoea. If liquids can be given by mouth, i.e., no frequent vomiting, no mental status changes, no risk of aspiration (fluids going down the wrong way), it is the best way to replace fluids and electrolytes and avoids costs and complications of intravenous therapy (phlebitis - inflammation/infection of the veins, accidental overdose of fluids, etc).

A bit of semantics here. Rehydration strictly means replacing lost water. When we have diarrhoea, we lose a lot more than just water. We lose a lot of solutes - mainly salts and sugars. Therefore, it is important to replenish the lost water content (rehydration) but also the lost volume of salts and sugars.

Water is absorbed by our intestines along with salt and sugars, specifically, sodium and glucose. Dilute hypotonic glucose-sodium solutions are highly effective in oral rehydration. Coconut water (or better yet, king coconut water) is nature’s best rehydration solution/energy drink, with the ideal mix of sugars and electrolytes you need. Homemade fruits juices, soups and broths also are great options for replacing the water and electrolytes that are lost through diarrhoea.

Antidiarrhoeal medications are rarely needed. Any infectious diarrhoea should be purged from the body - not kept inside. However, in cases of large volume diarrhoea poses a greatly increased risk of severe dehydration, antidiarrhoeal medicines may be helpful. Additionally, these medicines may be used on a very short-term basis for practical purposes - air travel, important meetings etc., where any kind of temporary relief may be highly beneficial.

The need for antibiotics, as well as the choice and duration of antibiotics, should be carefully discussed with an experienced care provider. Antibiotics are dangerous when misused and overused, and by themselves may worsen diarrhoea or cause severe forms of superimposed infections that give more diarrhoea, such as Clostridium difficile colitis….which must then be treated with even more antibiotics…you get the picture. Therefore, no self-medication with antibiotics please!