How can I tell if diarrhea is contagious?

In principle, only a medical examination followed by a laboratory examination of a stool sample can provide information about whether one is suffering from infectious diarrhea. However, one can also form a suspicious opinion with common sense. If several people in the immediate vicinity suffer from diarrhoea after a common meal, it is very likely that it is an infectious pathogen (from food).

The symptoms include frequent defecation more than three times a day. There is also an increased amount of stool, namely more than 250g per day. The consistency of the stool is also changed – to liquid or reduced.

Acute diarrhoea is often accompanied by vomiting and abdominal pain. The occurrence of frequent, small, liquefied, foul-smelling quantities of stool characterizes a special form of diarrhea, the paradoxical diarrhea. This is caused by constrictions (stenoses) in the large intestine, which prevent the normal transport of stool in the bowel.

In fact, only small amounts of stool pass the constriction. This is characteristic for tumors of the colon that constrict the interior. Another special form is the so-called false diarrhea, which occurs in irritable bowel syndrome.

In this case, the frequency of defecation is increased, but not the quantity and usually not the consistency. Diarrhea in combination with fever strongly suggests that it is an infectious pathogen. The substances (toxins) formed by bacteria, viruses or parasites trigger the body’s temperature regulation, which leads to increased core body temperature.

This reaction of the body should have the consequence that the respective pathogens are killed. If the fever exceeds 40°C, a doctor should be consulted, as these high temperatures can also be harmful to the body. If diarrhoea is accompanied by headaches, this is most likely due to a lack of fluids.

If you are able to absorb as much fluid through drinking as you lose through diarrhoea, your body should be able to compensate for the lack of fluid. If this is not possible, e.g. because you are also vomiting, or the diarrhoea is long lasting, it is worthwhile to give an infusion, i.e. fluid through the vein.

A description of the diarrhea is given not only by the frequency per day but also by the consistency or water content.By definition, one speaks of diarrhea if it has an increased water content of at least 75% and is present more than three times a day. In the case of diarrhea, which has the consistency of water, the water content is higher than 75%. If the diarrhea has a consistency similar to water, there is a risk of dehydration, i.e. that one loses too much water and dries out accordingly.

Therefore, if you suffer from diarrhea, you must make sure that you drink as much of the lost fluid as possible. Not only fluid is lost, but also important salts, whose loss can bring the body into imbalance. In order to replenish both the fluid and salt balance, electrolyte solutions that can be sold in pharmacies and drunk can be used.

This is especially recommended in cases of very watery diarrhea. In principle, blood in the stool can have several causes. In addition to chronic inflammatory intestinal diseases, malignant diseases (e.g. intestinal cancer) are also among the more serious causes.

Therefore, blood in the stool as well as blood deposits of any color should be taken to a doctor. The best known pathogen is the so-called EHEC, as it gained unintentional fame in public a few years ago (2011). This pathogen can even lead to death via the so-called HUS (hemolytic-uremic syndrome) because it also attacks the kidneys and the hematopoietic system.

Not least because of this one pathogen, it is important to clarify bloody diarrhea in the company of a doctor. In general it can be said that bloody diarrhea is more serious than bloodless diarrhea because it indicates a more severe course and a more threatening course of the disease.

If the source of bleeding is in the upper gastrointestinal tract, for example in the stomach, the stool cannot be identified as reddish, but as black.
It is then also called tar stool because the stomach acid in combination with fresh blood makes the stool tar-colored.
If there is a source of bleeding in the middle or lower gastrointestinal tract, such as a cancerous growth (carcinoma), the stool may well be reddish. One should be particularly suspicious of even bloody diarrhea in alternation with constipation.
Bright red blood deposits on the stool or toilet paper are an indication of hemorrhoids and are then rather unrelated to the cause of the diarrhoea. They nevertheless require clarification by a doctor.
Various infectious diarrhoea pathogens cause damage to the intestinal mucosa in their course of disease, which can lead to bloody and thin stool.

Vomiting or vomiting can be an accompanying symptom of diarrhoea. One speaks then of diarrhea with vomiting, regardless of whether the cause is an infection or food intolerance. Vomiting is caused when an irritation in the gastrointestinal tract reports severe nausea to the brain.

The stomach and oesophagus then react with a backward motion sequence to transport the stomach contents outwards via the oesophagus and mouth. This is a sensible protective measure for the body to protect itself against inedible or even dangerous food. If vomiting is felt to be too agonizing or does not stop on its own, it can be treated with medication.

If the vomiting is bloody or persistent, a doctor should be consulted. Young children and old people are particularly at risk for complications of vomiting because of the danger of loss of fluid and electrolytes (loss of salt). Nausea can be an accompanying symptom of diarrhoea, regardless of whether the cause is an infection or food intolerance.

It is caused by the fact that the entire digestive system, from the mouth to the anus, is fed by the same nerves. An irritation in the stomach or intestine caused by pathogens, for example, can then lead to a feeling of nausea in the brain and reflux (vomiting) due to the movements of the stomach and esophagus. In principle, the nausea has an important function, because it signals to the consciousness that something in the body is wrong.

The same applies to a possible resulting vomiting, because the body gets rid of the “bad” food. If nausea or vomiting persists, a doctor should be consulted. Abdominal pain is – not only in the case of diarrhoea – a very common symptom.

Therefore, if the symptom abdominal pain is associated with diarrhoea, a physical examination by a physician should take place to be able to make more detailed statements about the meaning of this pain.Here are the most important groundbreaking connections with abdominal pain: Last but not least, one should pay attention to the psychosomatic projection of negative thoughts or fears onto the abdomen. and gall bladder inflammation

A pressure pain in the right lower abdomen, for example, is most likely to be an acute appendicitis.
A diffuse abdominal pain of the entire abdomen below the ribcage, if crampy and persistent, may stand for the many contractions of the intestine, regardless of the cause of the diarrhea.
Pain in the right upper abdomen occurring in waves would tend to indicate a gall bladder inflammation.
Inflammation of the liver is also accompanied by right-sided pain in the upper abdomen, though not in waves, but permanently and with fever.

Pain in the right and middle upper abdomen indicates involvement of the stomach in an infection or food intolerance, e.g. lactose intolerance, because this also manifests itself with flatulence. However, they can also occur in chronic inflammatory bowel diseases.

Back pain in connection with diarrhoea is not a frequent concurrent complaint. Back pain in the sense of general aching limbs would indicate a viral or bacterial infection, especially if an elevated temperature occurs at the same time. If the back pain is more of a flank pain (i.e. side-down back pain), this could – in the case of highly acute diarrhea – stand for a severe fluid loss and a beginning kidney failure. If back pain existed already before the diarrhea, then these are not to be brought with the happening in the intestine in connection and should be clarified otherwise.