Digestive System

What is the digestive system?

Your digestive system is a group of organs that work together to digest and absorb nutrients from the food you eat. Digestion is a complicated process, and conditions and disorders can disrupt that process. Knowing how your digestive system works may help you keep it healthy and know when it may be time to get medical care.

What does the digestive system do?

It breaks down and absorbs nutrients from the food and liquids you consume. Your digestive system also takes care of food waste — the stuff that’s left over after you digest food. Your digestive system turns food waste into poop (stool).

What happens in the digestive process?

The digestive process involves lots of steps and several stops as food and liquid move through your digestive system:

1. Digestion starts even before you take that first bite of food. When you see and smell food, your salivary glands get to work. They release saliva so you have some spit in your mouth to moisten food when you start chewing.
2. Next, your chewed-up food moves from your mouth to your esophagus. Your esophagus uses a process known as peristalsis to send food to your stomach.
3. Your stomach releases acid and enzymes that break food down.
4. Next, your small intestine turns semisolid food into fluid to absorb nutrients.
5. Your pancreas and liver help by sending digestive juices to your small intestine. Your gallbladder contributes bile.
6. The final step is when your small intestine sends leftover food waste to your large intestine. That food waste becomes poop that leaves your body via your rectum and your anus (butthole).

What are the parts of the digestive system?

The main parts of your digestive system are your gastrointestinal (GI) tract and your biliary tract:

• Your GI tract is a series of hollow organs that connect to digest and move food through your body. It includes your mouth, esophagus, stomach, small intestine and large intestine.
• Your biliary tract makes and releases fluids that help digestion. It includes your bile ducts, gallbladder, liver and pancreas.

The gastrointestinal tract

Your GI tract is a long tube that runs from your mouth to your anus. If you could stretch it out, it would measure 30 feet (9 meters). It’s shorter in your body because your intestines — the longest parts of the tract — coil up in your lower abdomen (belly) under your stomach. Your GI tract parts are your:

• Mouth: This is where digestion begins.
• Esophagus: This is a tube in the center of your chest, behind your windpipe (trachea) and in front of your spine.
• Stomach: Your stomach sits in your upper abdomen on the left side of your body.
• Small intestine: This 22-foot-long muscular tube is the longest part of your gastrointestinal tract. It coils up in your lower abdomen and curves around your pancreas.
• Large intestine: The last step in the digestive process, the large intestine includes your colon, rectum and anus.

The biliary tract

Your biliary tract is in your upper abdomen (belly). Organs in your biliary tract support digestion by delivering bile and enzymes that help your small intestine break down food. Your biliary tract includes your:

• Bile ducts: You have bile ducts inside and outside your liver. They connect to your gallbladder.
• Gallbladder: Your gallbladder is tucked below your liver on the right side of your body.
• Liver: An organ and a gland, your liver is on the right side of your body under your ribs.
• Pancreas: This organ is behind your stomach and in front of your spine on the right side of your body.

What are some common conditions and disorders that affect the digestive system?

Many different conditions and disorders can disrupt your digestive system. Some are acute, meaning they don’t last for long. Others may be long-term or chronic illnesses. And some — like colon cancer, esophageal cancer or liver cancer — are serious diseases that can be life-threatening. Examples include:

• Acid reflux and GERD: Stomach acid that flows into your esophagus causes indigestion and heartburn.
• Celiac disease: This is an autoimmune disorder that’s triggered when you eat gluten, a type of protein.
• Constipation: Hard, dry poops from constipation are one of the most frequent gastrointestinal issues.
• Diarrhea: Loose, watery poop is one of the most common gut issues.
• Diverticulosis and diverticulitis: These conditions happen when little pouches (diverticula) develop in your colon.
• Gastroenteritis (stomach flu): Stomach flu is a viral infection in your stomach and intestines.
• Hemorrhoids: Swollen veins inside of your rectum or outside of your anus can itch and hurt.
• Inflammatory bowel disease (IBD): Crohn’s disease and ulcerative colitis are two common inflammatory bowel diseases.
• Stomach ulcers: These are open sores in your stomach lining.

What are common symptoms of digestive system disorders?

Almost all common digestive system disorders can cause the following symptoms:

• Abdominal pain.
• Constipation.
• Diarrhea.
• Nausea and vomiting.

If you’re like most people, you’ve had your share of occasional upset stomachs or loose poops that clear up within a few days. But any symptom that lasts for more than a few days, gets worse, or goes away and comes back is a reason to call a healthcare provider.

What are common tests to check the digestive system?

Healthcare providers may order one or more of the following tests to diagnose issues with your digestive system:

• Biopsy: Biopsies are procedures to get samples of tissue and fluid. Healthcare providers may order biopsies to diagnose digestive system issues like stomach ulcers or cancer.
• Blood tests: A healthcare provider may order tests like a complete blood count (CBC), basic metabolic panel (BMP) or a comprehensive metabolic panel (CMP) to diagnose issues with your digestive system.
• Bowel function tests: These include tests like anorectal manometry or defecography.
• Endoscopy: Providers do different types of endoscopies to examine the inside of your digestive system organs.
• Gastrointestinal (GI) exams: These exams involve X-rays that examine your GI tract.
• Stool tests: Medical pathologists look for germs or pathogens in your poop.

What are common treatments for these conditions and disorders?

Your digestive system is complicated because it contains many different organs. That’s why there’s no one treatment for conditions or disorders that can affect it. In general, healthcare providers recommend treatments like:

• Lifestyle changes: Changing what you eat, how you eat or even drinking more water may ease symptoms. For example, avoiding gluten is a treatment for celiac disease.
• Medication: Examples are corticosteroids to calm inflammation from Crohn’s disease or proton pump inhibitors (PPIs) for excess stomach acid.
• Surgery: Providers may do surgery to repair damage or remove a cancerous tumor.

How can I keep my digestive system healthy?

In general, the following are ways to keep your digestive system healthy:

• Drink enough water: Water helps the food you eat flow more easily through your digestive system. How much water you need depends on factors like your activity level, metabolism and size.
• Get your fill of fiber: Fiber helps digestion. Adding fiber to balanced meals of lean protein, fruits and vegetables can keep your digestive system working as it should.
• Add probiotics: Probiotics are good bacteria that fight off the bad bacteria in your digestive system.
• Eat mindfully: Mindful eating focuses on how and why you’re eating. Practicing mindful eating helps you to slow down and chew your food thoroughly.
• Avoid alcohol and smoking: Alcohol can increase the amount of acid in your stomach and can cause heartburn, acid reflux and stomach ulcers. Smoking almost doubles your risk of having acid reflux.
• Manage your stress: Stress is associated with digestive issues such as constipation, diarrhea and IBS (irritable bowel syndrome).