Diarrhea after Eating: Causes, Symptoms and Treatment

When you have diarrhea after eating and drinking, it can be caused by a number of reasons, from slightly irritant foods that hurry transit time like coffee to high probiotic foods like soured milk or high fiber foods like almonds. Causes may range from foods being simply not good for you or not fresh, in which case they may provide a medium for bacterial growth, to individual adverse reactions to particular foods or compounds in them of the likes of lactose, bromelain, sorbitol, caffeine or gluten. Some people suffer from so many different types of food intolerance that they get diarrhea after eating anything really. Any food that they don’t normally eat can lead almost immediately to loose stools and general stomach upset.

Diarrhea after eating can occur after any of the main meals or at night.
1) Diarrhea after breakfast. The likely culprit is often times coffee. Orange juice and coffee or milk and cereals and a fruit juice are also some unfortunate combinations that could cause loose stools after breakfast. Intake is also a factor. For example, while one cup of coffee might just encourage a bowel movement, 2 or 3 cups can potentially cause diarrhea.

Diarrhea after eating causes

2) Diarrhea after lunch. What you ate at breakfast, had before breakfast and lunch and at lunch can cause you to get diarrhea either immediately after lunch or several hours after. Think about what you ate and if there were foods you may be having adverse reactions to, foods or beverages that interact with medication, if you’re taking any, unfortunate combinations of foods such as soda and milk coffee. Or it could be either something you ate a couple of days back or a gastroenteritis manifesting just now.

3) Diarrhea after dinner. If it’s not an infection like a stomach bug you caught that morning or a flu that may be quick to act (a flu virus can sometimes incubate in as little as 8-10 hours), then it’s something you ate, either that day or several days leading up to it. From unwashed lettuce with E. coli or an intestinal parasite to milk that wasn’t refrigerated after opening or food that was left out for too long or undercooked, anything really can cause diarrhea at night, after dinner or later on.

Types of diarrhea

Why do you have diarrhea after eating? There are two main types of causes:
1) Infectious. Infectious diarrhea is essentially caused by food gone bad. Improperly stored food, whether raw or cooked, ultimately goes bad and, as it’s being decomposed, it becomes a great medium for bacteria growth and a source of infection. Some foods may be contaminated with irritants, pesticides, bacteria like E. coli on lettuce, intestinal parasites, even parasitic snails or fungi that produce mycotoxins. Viruses from other people who are sick can easily contaminate what you eat and drink and cause diarrhea.

2) Functional. Although it may sound better than infectious diarrhea, functional diarrhea is not always the lesser of two evils. In the happiest of situations, if you have functional diarrhea after eating, it may be caused by too many laxatives, too much fiber, too much magnesium or vitamin C, sorbitol, alcohol or prolonged use of antibiotics, one or multiple types of food intolerance or adverse reaction of some medication you take with your meal. But if you experience frequent diarrhea after eating that isn’t infectious in nature, doesn’t respond to dietary changes or lifestyle improvements, then you could be looking at conditions such as irritable bowel syndrome, colitis, ulcerative colitis, gut flora imbalances or, in rare cases, benign tumors or cancer.

The best way to identify the causes behind why you might be getting diarrhea after eating is to analyze your diet to avoid unfortunate combinations of foods (orange juice and coffee, cereals and milk and orange juice, soda and milk) and exclude potentially problematic foods one at a time for several days or weeks in a row to see if your health improves in any way. It’s just as important to have some tests done to exclude physical illness. And lastly, analyze accompanying symptoms. Any symptom preceding or following diarrhea after eating can be very telling as to the underlying causes.

Diarrhea after eating and drinking

List of symptoms

The most and least common symptoms include:
1) Nausea and vomiting.
2) Fever, low or high grade, alternating with chills.
3) Cold sweats.
4) Lightheadedness, dizziness, blurred vision, headaches.
5) Stomach upset, cramps, aches, back pain.
6) Bloating, gas, burping, stomach heaviness.
7) Abnormal bowel movements: pain before, during or after having a bowel movement (abdominal cramps, back pain, tailbone pain, leg pain), itching, bleeding, burning sensation, stools that float, abnormal stool colors like green or pale, clay-colored stools (see Stool Colors: What They Mean), diarrhea alternating with constipation, foul smelling stools and other similar symptoms.

Other examples

1) Diarrhea after coffee. Coffee hurries transit to the point it forces a bowel movement, even if the normal transit cycle has not been completed. This results in stools that aren’t well processed and may be too loose. Coffee is also an irritant for the gastrointestinal mucosa. Diarrhea after drinking coffee is actually quite common in perfectly healthy people and those with inflammatory gastrointestinal conditions like irritable bowel syndrome or colitis.

2) Diarrhea and fever after eating. Whenever there is fever, there is also usually an infection. And loose stools and fever, whether low or high-grade, indicate either a stomach bug or stomach flu (gastroenteritis) or influenza. Nausea, vomiting, weakness and fatigue also point out to infectious causes. If you experience coughing, severe muscle aches, runny nose and chest discomfort, it’s likely influenza. Diarrhea and vomiting after eating and drinking can be caused by either gastroenteritis or influenza and may last anywhere between 24 hours to 4 days.

3) Diarrhea after beer. When the beer is too cold and you drink it really fast, the low temperature of the beverage contrasts with the relatively warm temperature of the body. This stimulates the vagus nerve and the intestinal wall muscles to contract, automatically pushing food down, even if it’s not quite ready. And the resulting bowel movement is too loose. It’s the same thing that happens when you drink cold water or ice water. Some people are either allergic to the cereal grains the beer is brewed from, whether it’s barley, rye, oats or wheat or the gluten in barley, rye and wheat. Some people exhibit an intolerance to brewer’s yeast that can cause stomach upset and diarrhea. Others are simply more sensitive to fermented products in general.

4) Diarrhea after pizza. Eating too much pizza at once, being sensitive to the yeast used to puff pizza dough or to the gluten in the wheat flour used for the dough can lead to loose stools. Some people just experience diarrhea after eating carbs in general, not just pizza.

5) Diarrhea after eating avocado. Avocado is one of those foods that is good for some people and bad for others. It is not uncommon for the fruit (yes, avocado is a fruit, a berry more exactly) to lead to loose, even watery stools if you have an allergy to the fruit or an adverse reaction to its high fat content (read more about the 8 Side Effects and Contraindications of Avocado).

6) Diarrhea after eating salad. Lettuce, spinach, endives, beet greens, dandelion leaves, kale and all leafy vegetables that may go in a salad can cause loose, watery stools. If you eat too much, it’s likely because of the fiber. If you don’t eat too much, it could be because of a bacterial infection or an intestinal parasite that you may have ingested from the unwashed or improperly washed leaves. Pathogenic strains of E. coli and other bacteria can easily contaminate leafy greens from irrigation water, for example.

7) Diarrhea after eating eggs. Eggs are one of those foods that spoil quickly. Raw, undercooked or contaminated eggs and by-products like mayonnaise, eggs with cracked shells, especially those that have been left at room temperature can be a source of infection. Remember to refrigerate your eggs, discard the ones with damaged shells and refrigerate any dishes containing eggs immediately after preparation.

8) Diarrhea after beet juice. Diarrhea after drinking beet juice can be caused by a compound in the vegetable juice called adipic acid which is a mild irritant. This compound can induce peristaltic movements and shorten transit time as a result, causing loose stools. And because of the strong pigmented betaine in the vegetable root, you can get red diarrhea after your drink beet juice, depending on how much of it you drink. Too many liquids at once, sweeteners in commercial juices like sorbitol, lack of pasteurization causing bacterial overgrowth, serving the juice cold, with ice, fiber intake or sensitivity to various compounds in the juice can also lead to watery stools.

9) Diarrhea after eating candy or sugar-free chewing gum. Any diet food that uses artificial sweeteners, especially sorbitol, can cause diarrhea in those sensitive to the sweetener. Whether it’s mints, chewing gum, cough syrup or sweets, read the label to find the connection and learn what may be causing the side effects.

10) Diarrhea after eating other foods:
– pineapple: possible side effect of the enzyme bromelain in pineapple and juice.
– oatmeal: caused by the high fiber intake (if you eat it every day) or gluten content, oat sensitivity to the proteins in oats, cross-contamination with other grains.
– corn (maize): allergic reaction to lipid transfer proteins in corn (maize allergy), cross-contamination with other grains, contamination with pesticides.
– almonds: side effect of the high fiber content (100 g of almonds: 12.2 g of dietary fiber), intolerance or allergy to almonds, adverse reaction to aflatoxins.
– peaches: intolerance to peach proteins, allergic reactions (to the fresh fruit or sulfur dioxide in the dried fruit) or adverse reaction to sorbitol, a sugar alcohol in peaches.
– apples: eating too many apples with skin can lead to diarrhea because of the pectin in skin (or constipation in some people); apples also contains sorbitol which may act as a laxative.
– dried plums (prunes): high fiber content and sorbitol content may have strong laxative effects.
– chocolate: cocoa allergy can cause loose stools in addition to urticaria, breathing difficulties and anaphylaxis, milk in chocolate can lead to diarrhea in those with lactose intolerance, possibly worse in those with celiac disease.
– milk and dairy: lactose intolerance or side effect of eating fermented foods containing beneficial bacterial cultures.

11) Diarrhea after eating anything can be caused by a stomach infection like gastroenteritis or respiratory infection like influenza (also read Influenza and Fainting: Causes and Treatment). Symptoms like fever, chills, nausea, vomiting, severe muscle aches, lack of appetite or inability to keep food and water down indicate an infectious cause. At the same time, if you seem to have diarrhea after eating anything without those symptoms, it could be you are having more than one type of food intolerance or an intolerance to one compound found in more foods that you are eating. For example, inulin sensitivity can be triggered when you eat garlic, onions, banana or drink coffee substitutes like chicory root or dandelion root.

What to do about it

Prevention and treatment include addressing the following aspects:
1) Avoid touching your face or eating without washing hands first.
2) Discard expired foods, bad smelling foods, eggs with a cracked shell, old food.
3) Refrigerate food, especially shellfish and fish, milk, eggs and meat.
4) Access to clean drinking water is essential.
5) Wash vegetables and fruits you eat raw very well.
6) If you have symptoms such as fever, vomiting, blurry vision, dizziness, fainting and cannot keep food or water down, seek medical help because you may be dealing with an infection. You might need antibiotics, antidiarrheal medication or antiparasitics. Keep hydrated, rest and eat well.
7) Learn about which foods are good for you and which are not and avoid those that trigger side effects for you. Avoid problematic combinations like soda and milk. Manage existing conditions like IBS or celiac disease with a proper diet. Absolutely avoid foods you are allergic to.

This post was updated on Saturday / August 1st, 2020 at 5:47 PM