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The Digestive Process: How Is Food Digested in the Stomach?

Few activities in life seem as natural as eating and drinking. You do them every day without giving them much thought. Yet, what happens inside your body after you eat is complex. The digestive process pulls out the energy you need to function, and then gets rid of what’s left behind.

When you chew and swallow, a well-orchestrated chain of events takes place inside your body that you are not aware of. Peristalsis is an involuntary muscular action that pushes food through your digestive system. It's an important part of the digestive process. If you were to watch this process on an X-ray, it would almost look like an ocean wave pushing food from one organ to the next. In the first step of this journey, food moves down your food pipe (esophagus). This takes it from your throat to your stomach.

What goes on in the stomach

The gateway to your stomach is called the lower esophageal sphincter. This ring-like muscle opens and closes the passage between your esophagus and your stomach, as needed. During the digestive process, the sphincter relaxes and lets food pass into your stomach.

Food goes through a significant part of the digestive process inside your stomach. You may think of your stomach as a simple pouch. But it’s actually much tougher than other organs in your body. For example, the digestive juices and enzymes that your stomach makes to break down food could dissolve most of the other organs in your body. Your stomach contains a thick mucous lining that prevents these strong juices from eating through its walls.

The stomach is also very flexible. When your most recent meal first enters your stomach, the upper part relaxes and expands. This lets your stomach hold and process a large amount of food and liquid.

During digestion, muscles push food from the upper part of your stomach to the lower part. This is where the real action begins. This is where digestive juices and enzymes break down the food that you chewed and swallowed. It prepares it to provide your body with energy.

The stomach makes several digestive juices and enzymes that mix with food. Next, the stomach’s strong muscles act like a blender to turn food into a useable form.

This process takes longer for some types of foods than others. Carbohydrates, for example, break down the fastest. This explains why many recommend carb-heavy foods for a quick energy boost. Proteins take longer to digest and exit the stomach. Fats take the longest time of all. Zero-calorie liquids, such as water, empty the fastest from the stomach.

Leaving the stomach

Once the stomach completes its role in the digestive process, its contents slowly pass into a short tube at the base of the stomach. This is called the duodenum. It's the first part of the small intestine. Here the next stage of digestion takes place. Digestive juices produced in organs, such as the liver and pancreas, continue the process of turning food into energy.  

Online Medical Reviewer: Jen Lehrer MD
Online Medical Reviewer: Rita Sather RN
Online Medical Reviewer: Tara Novick BSN MSN
Date Last Reviewed: 2/1/2023
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