Gastrocolic Reflex

What is the gastrocolic reflex?

The gastrocolic reflex is an automatic communication between your stomach (gastro-) and colon (-colic). When food enters your stomach, nerves send signals to the muscles in your colon that trigger them to start moving. This is why you might feel like you need to poop soon after you eat. When a new batch of food begins the digestive process, your body makes sure to move the last batch out to make room for it.

What is an overactive gastrocolic reflex?

You might have an overactive gastrocolic reflex if you frequently feel an urgent need to poop right after eating, and the muscle movements in your bowels feel very strong. Urgent bowel movements can happen occasionally for lots of reasons: Certain foods, medications, infections and stress can trigger them. But if you have these symptoms all the time, you could have a type of functional GI disorder.

What is the purpose of the gastrocolic reflex?

The gastrocolic reflex is how your stomach tells your intestine that more food is coming, so the old food needs to move out. It’s one of many reflexes that happen during the digestive process to keep things moving. Like factory workers on an assembly line, each organ in your GI tract must do its part in a timely and coordinated way. This keeps the product (food) moving forward on the conveyor belt (your GI tract).

What body parts are involved in the gastrocolic reflex?

Reflexes in your GI tract trigger movement through a complex signaling process that involves muscles, nerves and hormones. Some of the important players involved in the gastrocolic reflex include:

• Your stomach: Food entering your stomach starts the digestive process. Muscles in your stomach stretch to make room for food and then churn it to start breaking it down.
• Your colon: Your colon is the last part of your food’s journey through your GI tract. It moves slowly most of the time, absorbing water from your food and turning it into solid waste.
• Your enteric nervous system: Also known as the “brain in your gut,” your enteric nervous system is a network of nerves within your GI tract that manages its automatic functions.
• Smooth muscles: These muscles line the walls of your GI tract and respond automatically to signals from your nervous system. They move your food through the digestive process.
• Gastrin: Gastrin is a hormone that stimulates contractions in your stomach. Nerves in your stomach release gastrin when they detect your stomach stretching to make room for food.
• Cholecystokinin: Cholecystokinin is a hormone that triggers contractions in several other organs. Food passing from your stomach to your small intestine triggers cholecystokinin.

How does the gastrocolic reflex work?

The primary trigger for the gastrocolic reflex is stretching in your stomach to make room for food. A larger meal means more stretching, which tells your whole digestive system to make more room. Nerves in your stomach detect when it stretches and signal to your colon muscles to start moving waste out. Your colon responds with a series of large, wave-like contractions, called “mass movements.”

Researchers have also found that the content of your meal can affect how strong your gastrocolic reflex is. A higher-calorie meal with more fats and proteins to digest triggers more digestive hormones, like gastrin and cholecystokinin, to release. These hormones trigger your digestive juices, like gastric acid, enzymes and bile. They also seem to stimulate greater contractions in your small intestine and colon.

How long does the gastrocolic reflex normally take?

You may start feeling movement in your colon within minutes of eating, or within about an hour. This is the gastrocolic reflex in action. But movement doesn’t necessarily mean you’ll poop right away. The gastrocolic reflex can last anywhere from a few minutes to a few hours. In general, it tends to work more quickly in young children and more slowly in adults. It’s normal for infants to poop right after feeding.

What causes an overactive gastrocolic reflex?

If your gastrocolic reflex feels too strong, too fast or uncomfortable, it could be related to what you’ve just eaten. High-calorie foods, greasy foods and spicy foods can cause greater contractions in your digestive system. Hidden food intolerances could also cause this reaction. Drinks containing alcohol or caffeine can make you poop. Try to notice which foods trigger your symptoms and avoid those foods.

If your symptoms have lasted for several weeks and changes to your eating habits haven’t helped, see a healthcare provider. See your provider if your symptoms include colon spasms, frequent diarrhea or weight loss.

What gastrointestinal disorders involve your gastrocolic reflex?

These conditions may involve problems with your gastrocolic reflex:

• Irritable bowel syndrome (IBS): IBS causes discomfort in your bowels when it’s time for them to move. One type involves chronic diarrhea, and the other involves chronic constipation.
• Dumping syndrome: Dumping syndrome causes your stomach to empty food too quickly into your intestine, speeding up its journey. It can also stimulate your gastrocolic reflex.
• Gastroparesis: Gastroparesis means stomach paralysis. It’s related to nerve damage or impairment. This damage delays stomach emptying and your gastrocolic reflex.
• Inflammatory bowel disease (IBD): Diseases that cause chronic inflammation in your colon can make it more sensitive and reactive. This might cause an overactive gastrocolic reflex.

What is the treatment for an underactive or overactive gastrocolic reflex?

For adults with temporary symptoms, changes in eating patterns are most likely to help. If you continue to have symptoms, you can discuss them with your healthcare provider for further evaluation and care. On a case-by-case basis, they might prescribe medications to stimulate or slow down your bowels.