Why do I have to poop right after I eat?

Gastrocolic reflex | Causes | GCR vs. diarrhea | GCR vs. fecal incontinence | How to reduce the intensity of GCR | When to see a healthcare provider

People have bowel habits at varying frequencies and ranges. After eating a meal, a person might feel the sudden urge to poop. Pooping right after eating may indicate that someone has an overactive gastrocolic reflex or GCR. Typically, having an overactive GCR isn’t a major concern, although, in some instances, it may suggest an underlying health problem.

Why do I have to poop right after I eat?

The reason why a person moves stool (or poop) right after eating is due to their GCR.

“The GCR is a physiological reflex that increases the motility of the lower gastrointestinal tract (colon) in response to a meal,” says Caroline Soyka, DO, a board-certified gastroenterologist with Gastro Health of Jupiter, Florida. “Essentially, when the stomach stretches after food ingestion, it sends a message to the colon to ‘start squeezing.’”

According to Dr. Soyka, some people have faster or more overactive gastrocolic reflexes than others, but it may not be a significant health concern. “If the issue is just rapid GCR, then treating it depends on how much stooling after a meal bothers the person or interferes with their quality of life,” Dr. Soyka adds.

Aside from an overactive GCR, there are other possible reasons for pooping shortly after eating, but a fast metabolism is not one of them.

“This is a frequent myth, but no, just because food moves through your body quickly does not necessarily mean you have a fast metabolism,” says Megan Hilbert, MS, RDN, a registered dietitian at Top Nutrition Coaching based in Madison, Wisconsin. “Metabolism has more to do with how efficiently your body utilizes the energy to absorb from a meal.”

What causes an overactive gastrocolic reflex?

Certain conditions may cause someone to develop an overactive gastrocolic reflex, such as:

• Irritable bowel syndrome (IBS)
• Inflammatory bowel disease (IBD)
• Small intestinal bacterial growth (SIBO)
• Dumping syndrome
  

Here’s a deeper look into how these health conditions are tied to overactive gastrocolic reflexes.

Irritable bowel syndrome (IBS)

Irritable bowel syndrome (IBS) is a chronic condition involving a group of symptoms that affect a person’s digestive system, including cramping, abdominal pain, bloating, diarrhea, and constipation.

According to research, people with IBS might have a strong urge to poop right after eating a meal. Alongside an overactive gastrocolic reflex, they may experience symptoms like abdominal bloating, gas, pain, and irregular bowel habits.

Inflammatory bowel disease (IBD)

IBD is the umbrella term for a group of health conditions that cause inflammation in the digestive tract. Common types of IBD include ulcerative colitis and Crohn’s disease. 

The relationship between an overactive gastrocolic reflex and IBD is similar to that of the condition and IBS, as people with IBD can also experience abdominal pain, nausea, diarrhea, and severe urgency to poop. However, patients with IBD can also experience bloody diarrhea, joint pains, and the frequent urge to pass stool without being able to do so (called tenesmus).

Small intestinal bacterial growth (SIBO)

Small intestinal bacterial growth (SIBO) is where excess colonic bacteria grow in the small intestine. People with SIBO may experience symptoms that can lead to an overactive GCR, such as bloating, gas, abdominal distension, cramping, and diarrhea. 

Dumping syndrome

Dumping syndrome is when food moves too quickly through the stomach and small intestine after eating. According to research, an overactive gastrocolic reflex is a common health problem among people with dumping syndrome.

Gastrocolic reflex vs. diarrhea after eating

While they may seem similar, there are a few differences between gastrocolic reflex and diarrhea.

One way to differentiate between gastrocolic reflex and diarrhea is to examine the effects each can cause after eating.

“Diarrhea after eating is a condition that involves passing loose, watery stools shortly after meals and is called postprandial diarrhea,” says Kenneth Brown, MD, a board-certified gastroenterologist and founder and chief medical officer of Atrantil of Plano, Texas. “Unlike the normal gastrocolic reflex, postprandial diarrhea is often accompanied by other symptoms like abdominal cramps, urgency and bloating.”

The most common symptoms associated with diarrhea include the following:

• Loose, watery stools
• Loose stools that occur three or more times a day
• Abdominal pain
• Abdominal cramps
• Urgent need to use the bathroom
• Failure to control bowel movements
  

Like overactive GCR, diarrhea may occur due to conditions like IBS, IBD, and SIBO—but what separates this condition is that it can arise from other medical reasons, including:

• Viral, bacterial, and parasitic infections
• Eating contaminated food or drinking water
• Food allergies
• Food intolerances, such as lactose intolerance
• Abdominal surgery like bowel resection
• Long-term use of certain medications

As mentioned previously, the gastrocolic reflex is a normal response everyone experiences when digesting food. However, in some instances, an overactive gastrocolic reflex may lead to faster bowel movements after eating.

“This reflex stimulates movement in your gastrointestinal tract, particularly your colon, leading to the urge to have a bowel movement,” Dr. Brown explains. “This reflex is often stronger after a large meal or certain types of food (like high-fat or spicy foods).”

However, in some cases, diarrhea or the inability to reach the bathroom in time may indicate that someone has an overactive gastrocolic reflex. With this in mind, it is important to understand whether diarrhea is causing a stronger gastrocolic reflex or if there’s another condition causing pooping after eating.

“If you notice a pattern of experiencing diarrhea frequently after eating, this could be due to a particularly strong gastrocolic reflex,” says Hilbert. “If diarrhea seems to occur less frequently or more sporadically instead of after eating, this could be due to a variety of factors and symptoms unrelated to having a strong gastrocolic reflex.”

Gastrocolic reflex vs. fecal incontinence

Fecal incontinence is a potential reason why some people feel the sudden urge to poop after every meal.

“Fecal incontinence is defined as the inability to control bowel movements resulting in involuntary soiling,” Dr. Soyka says. “This can further be defined as urge incontinence (you feel the urge to go but ‘can’t make it’ in time) versus passive fecal incontinence (passing stool without even knowing it).”

The symptoms of fecal incontinence may include the following:

• Inability to hold gas
• Stool leakage during daily activities or exertion
• Inability to reach the toilet in time for bowel movements

According to Dr. Soyka, the common causes of fecal incontinence are:

• Watery diarrhea
• Pelvic floor muscle weakness or uncoordinated muscle contraction/relaxation 
• Overflow from colon blockage
• Muscle or nerve damage
• Organ prolapse
• Scar tissue

While fecal incontinence and gastrocolic reflex can affect digestive health, it is easy to differentiate between them. For example, the gastrocolic reflex typically occurs after eating, while fecal incontinence can occur at any time and involves involuntary stool loss, according to research.

How to reduce the intensity of the gastrocolic reflex

If someone is dealing with a strong gastrocolic reflex, there are ways to minimize or lessen its effect.

Below are some tips for managing an overactive gastrocolic reflex.

Find the root cause of gastrocolic reflex

Since several conditions can cause an overactive GCR, a person needs to determine if there are any undiagnosed health problems. “Understanding the root cause can help make some lifestyle changes like avoiding certain foods, eating smaller, less spicy meals as well,” Dr. Brown says. “If there is an association with IBS or SIBO, then treating the offending bacteria while feeding the good in the microbiome can be done.”

Change dietary habits

Choosing healthier foods may reduce the intensity of a strong gastrocolic reflex. “For most people, IBS plays a role, so decreasing trigger foods, such as FODMAPS, and seeing a registered dietitian for support are especially helpful,” Hilbert says.

FODMAP is an acronym standing for fermentable, oligo-, di- and monosaccharides, and polyols. These are short-chain carbohydrates known to worsen or encourage gastrointestinal symptoms, including cramping, bloating, and diarrhea.

Some examples of high FODMAP trigger foods to avoid include:

• Dairy products, such as milk, yogurt, and ice cream
• Wheat-based products, such as bread, cereal, and crackers
• Beans and lentils
• Certain vegetables, such as artichokes, asparagus, onions, and garlic
• Certain fruits, such as apples, cherries, pears, and peaches

To combat unpleasant gastrointestinal symptoms, a healthcare provider or dietitian may recommend a low FODMAP diet, which can include foods like:

• Eggs
• Meat
• Certain cheeses, including brie, Camembert, cheddar, and feta
• Almond milk
• Whole grains, such as rice, quinoa, and oats
• Certain vegetables, including eggplant, potatoes, tomatoes, cucumbers, and zucchini
• Certain fruits, such as grapes, oranges, strawberries, blueberries, and pineapples
  

A healthcare provider or nutritionist can provide a more extensive list of low-FODMAP foods to improve gastrocolic reflex.

Practice mind-gut exercises

Stress, anxiety, sadness, and depression can all contribute to or worsen GI conditions, such as IBS, IBD, gastroesophageal reflux disease (GERD), and others. When this occurs, the digestive process is negatively impacted, which then can return to the brain, causing a cycle of emotional and digestive problems.

Research reveals that an increase in gut inflammation and microbiome may affect other areas of the body, leading to fatigue, depression, and even cardiovascular disease.

According to research, the gut microbiome holds trillions of bacterial microbes that encourage digestion and food absorption for energy production.

Engaging in mind-gut exercises may encourage better gut and brain health.

“Mind-gut-based exercises like yoga, meditation, etc., can help reduce the gastrocolic reflex over time,” Hilbert says.

In addition to yoga and meditation, other mind-gut exercises include breathing exercises, mindfulness, and gut-directed hypnotherapy.

Try peppermint oil

Another natural method for relaxing the gastrocolic reflex is taking peppermint oil. Research suggests that peppermint oil may relieve uncomfortable gastrointestinal symptoms due to its anti-microbial and anti-inflammatory effects. Peppermint oil has been shown to improve digestion by relaxing the smooth muscles responsible for bowel movements.

In the same research study, while peppermint oil has few side effects, it seems to help people with IBS, functional dyspepsia, childhood functional abdominal pain, and postoperative nausea.

Prescription medications

If natural methods are ineffective in improving the function of the gastrocolic reflex, medical treatment may be necessary.

“Medications can speed up and slow down the reflex,” Dr. Soyka says. “Different medications have been shown to slow the reflex—examples include antispasmodics, tricyclic antidepressants, SSRIs, and ondansetron.”

It’s important to note many treatments that may help with overactive gastrocolic reflex are typically prescribed to help with IBS symptoms because, as previously mentioned, IBS may lead to health issues with gastrocolic reflex.

Antispasmodics are a group of medicines used to treat symptoms of IBS by decreasing the sensitivity of and relaxing smooth muscles and relieving abdominal pain and discomfort.

Certain antidepressants can help regulate irregular bowel movements and other symptoms, such as tricyclic antidepressants. These medicines have shown to be an effective second-line treatment for IBS but can have some serious side effects.

Selective serotonin reuptake inhibitors (SSRIs), another type of antidepressant, may alleviate a strong gastrocolic reflex. Still, research suggests this medicine may cause gastrointestinal symptoms, such as diarrhea, loose stools, and constipation.

Ondansetron (brand name Zofran) is a medication commonly used to treat nausea and vomiting caused by cancer drug treatments like chemotherapy and radiation therapy. This medication may help people with IBS by relieving symptoms like loose stools and the frequency and urgency of bowel movements.

When to see a healthcare provider

The gastrocolic reflex is a normal physiological reflex that stimulates the movement of stool after eating. When people have a stronger gastrocolic reflex, they may poop right after finishing every meal. Pooping after eating is normal, but certain medical conditions may cause an overactive gastrocolic reflex.

If someone is concerned about their bowel movements, it’s recommended that they seek medical attention.

“A person should seek out professional help for these concerns if any of them are new or if they have any red flag symptoms such as blood in the stool, change in stool caliber, unintentional weight loss, abdominal pain, etc.,” Dr. Soyka says. “Additionally, if a person’s stool patterns are affecting their quality of life, then they should seek an appointment with a gastroenterologist.”