Overindulging in certain foods or beverages and overeating in terms of larger than normal quantities of food intake can lead to diarrhea for several reasons. Sometimes this diarrhea can start during or immediately after eating, while at other times it may arise hours or even a day or two later. There may be no signs of an infection or food poisoning and it can even occur with foods that a person usually eats.
Diarrhea with overeating or bingeing should be seen as a sign of gastrointestinal disturbances. Too much of food can be harmful in various ways, especially in the long term. While this overindulgence may lead to only short term diarrhea, there are instances where there may be recurrent or even persistent loose, watery and frequent stool. It may also occur with regular bingeing as is seen in certain eating disorders such as bulimia nervosa.
Read more on overeating.
Causes of Overeating Diarrhea
Normally the food that we eat is processed over hours and days. It is digested, nutrients are absorbed and waste materials left in the gut to be expelled as stool. It can take remnants of food that is consumed up to 72 hours to be passed out in the stool. This is known as the bowel transit time. People who experience diarrhea tend to have a fast bowel transit time meaning that food, fluids and wates move through the gut much faster.
Most of the time we control the amount of food that we consume per meal. However, there are times where we all overeat, like during festivities. This puts a strain on the digestive system to process food faster and can eventually irritate the system and lead to forceful expulsion of the excess food through vomiting or diarrhea. Some of the reasons for this disturbance are discussed below.
Stretching of Stomach and Bowels
There are several reflexes that involve the upper, mid and lower parts of the gut. These reflexes are a result of signals generated in one part of the gut then causing an effect in another part of the gut due to nerve pathways. When it comes to overeating, stretching of the stomach and upper bowel can stimulate contractions in the colon that leads to a bowel movement.
The gastrocolic and duodenocolic reflexes are the two main defecation reflexes responsible for mass colonic movements when the stomach or duodenum stretches, respectively. This stretching is due to the excessive consumption of food. This bowel movement may not always be diarrhea. However, if the overeating is excessive or continued or if there are other factors that can alter stool formation then diarrhea could result.
Read more on defecation reflexes.
Microbes and Toxins
Microorganisms like bacteria and other infectious agents such as viruses are widespread in our environment. Small amounts of bacteria and viruses are present in our food even if we practise good hygiene, cook food thoroughly and refrigerate timeously. Apart from originating from uncooked food and water, bacteria and viruses are floating in the air and constantly settling on food. However, most of the population of these microbes (inoculation dose) are usually too small to trigger irritation or an infection and lead to diarrhea.
With overeating, the intake of otherwise small amounts of these microbes will be greater than normal. As a result, this higher inoculation dose of infectious agents can then lead to an infection. However, if food hygiene practises are poor, if food is not properly cooked, if contaminated water is used in food preparation or if food is not properly refrigerated then even a small quantity of this tainted food can lead to infections like gastroenteritis or result in food poisoning.
The term food intolerance usually refers to the inability to digest certain nutrients in foods. For example in lactose intolerance the body lacks the enzyme to digest the milk sugar known as lactose. Therefore a person will experience gastrointestinal upset with consuming milk and dairy. Another type of food-related problem is malabsorption where the body cannot absorb certain nutrients. Both an intolerance and malabsorption syndrome can lead to diarrhea.
For some people with milder forms of these food-related syndromes there may be little to no symptoms. For example almost 70% of the world’s population has lactose intolerance but not everybody experiences symptoms. However, in the event of overeating and therefore consuming large quantities of trigger foods, symptoms like diarrhea suddenly arise. This may be further complicated by the other mechanisms associated with overeating diarrhea like stretching of the stomach and bowels.
A number of different substances can serve as gastrointestinal irritants. In small quantities there may be little to no irritation and therefore no symptoms such as diarrhea. However, with overeating the intake of these irritants can be large enough to lead to symptoms like diarrhea. These irritants may include certain preservatives or food additives, alcohol or stimulants like caffeine.
Treatment of Overeating Diarrhea
Diarrhea due to overeating usually does not require any specific treatment. It is short-lived and resolves on its own. However, in some instances drugs like antibiotics may be necessary for bacterial gastroenteritis. Antidiarrheal agents like loperamide should not be the first choice of treatment. Rather the diarrhea should run its course so that the gut can evacuate the excess food, infectious agents, toxins and irritants.
- Ensure adequate rehydration with oral rehydrating solutions (ORS) for the optimal concentration of electrolytes and sufficient water intake.
- Minimize any further large meals and avoid foods that were previously eaten than ma be responsible for the diarrhea. Rather opt for a bland diet of freshly cooked foods.
- Rest is important while the diarrhea persists as physical activity can speed up fluid and electrolyte loss. Bed rest is advisable but even staying active and avoiding exertion will suffice in milder cases.
- Use probiotics to help restore the normal intestinal flora (‘good bowel bacteria’). However, dairy should be minimized because short term secondary lactose intolerance can arise with diarrheal illnesses.
- Beware of the signs of dehydration as this is the main complication of any cause of diarrhea. Immediate medical attention is necessary when moderate to severe dehydration becomes evident.