Digestion depends on many organs working together. When one part of the digestive system is not functioning properly, digestion can be affected. The following sections describe some of the most common digestive disorders.

Heartburn and Gastroesophageal Reflux

Heartburn is a burning sensation in the chest (behind the breastbone) or throat. It is the most common symptom of gastroesophageal reflux (GER), a condition in which acidic chyme from the stomach flows backward into the esophagus and sometimes into the mouth.

Occasional GER and heartburn are common, especially after eating large, greasy, or spicy meals. However, when reflux occurs frequently (typically more than twice a week) or causes damage to the esophagus, it may be diagnosed as gastroesophageal reflux disease (GERD).

GERD is one of the most common gastrointestinal disorders in the United States, affecting approximately 20% of adults. In addition to heartburn, GER and GERD may cause difficulty when swallowing, a persistent sore throat , nausea, or vomiting. Because chronic reflux can damage the lining of the esophagus and increase the risk of esophageal cancer, persistent symptoms should be evaluated by a physician. ^[1]

Managing Heartburn and Gastroesophageal Reflux

Symptoms of GER and GERD can often be improved with diet and lifestyle changes. Helpful strategies include:

• Avoid trigger foods such as greasy or spicy foods, chocolate, coffee, alcohol, and acidic foods (e.g., tomatoes and citrus fruits).
• Eat small,  frequent meals.
• Avoid eating within 3 hours of bedtime, and remain upright after meals.
• Wear loose-fitting clothing around your abdomen.
• Elevate the head of the bed by 6 to 8 inches.
• Quit smoking and avoid secondhand smoke.
• Achieve and maintain a healthy body weight, if needed.

Over-the-counter antacids (e.g., Maalox, Mylanta, and Rolaids) can provide temporary relief from occasional heartburn. People with frequent or persistent symptoms should consult a healthcare provider for evaluation. GERD may require prescription medications that reduce stomach acid, and in severe cases, surgery may be recommended.

Peptic Ulcers

A peptic ulcer is an open sore that develops in the lining of the stomach or duodenum (the first part of the small intestine). Less commonly, ulcers can occur in the esophagus. They develop when the protective mucus layer is damaged, allowing stomach acid and the digestive enzyme pepsin to erode the underlying tissue.

Peptic ulcer disease affects millions of people worldwide, although the number of cases has declined in recent decades because of more effective treatment.

The two most common causes of peptic ulcers are infection with Helicobacter pylori (H. pylori) and long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen. H. pylori is a bacterium that can survive in the stomach’s acidic environment and damage the protective mucus lining. About half of the world’s population carries H. pylori, although most infected people never develop ulcers. NSAIDs increase ulcer risk by reducing the production of substances that help protect the stomach lining.

Common symptoms include a burning or gnawing pain in the upper abdomen, often when the stomach is empty. Some people also experience bloating or nausea. More serious ulcers may bleed, causing blood in the vomit or stool, or perforate the wall of the stomach or intestine, creating a medical emergency.

Treatment depends on the underlying cause. Ulcers caused by H. pylori are treated with antibiotics to eliminate the infection and acid-reducing medications to promote healing. When NSAIDs are responsible, treatment usually includes stopping or reducing these medications, when possible, along with acid-reducing drugs. Most peptic ulcers heal successfully when the underlying cause is treated.

Diarrhea and Constipationantibiotics

 Diarrhea and constipation occur when waste moves through the large intestine either too quickly or too slowly.

Diarrhea 

Diarrhea is the frequent passage of loose, watery stools caused by waste moving too quickly through the large intestine. It occurs when waste moves too quickly through the large intestine, preventing enough water from being absorbed. The most common causes are infections from contaminated food or water, including bacteria (such as E. coli and Salmonella), viruses (such as norovirus and rotavirus), and parasites (such as Giardia)—the same types of microorganisms discussed in Chapter 1.  Food allergies, food intolerances, certain medications, and digestive disorders can also cause diarrhea.

The greatest concern of diarrhea is dehydration, especially in infants, young children, and older adults. Prolonged diarrhea may also reduce nutrient absorption.

MANAGING DIARRHEA

You may have heard from your parents and  grandparents about the BRAT diet (bananas, rice, applesauce, and toast).  It was once commonly recommended to treat diarrhea. Eating these bland foods for a day or two is generally safe if they are all you can tolerate. However, healthcare providers now encourage people to return to a balanced diet as soon as they are able because the BRAT diet alone does not provide adequate nutrition for recovery.

The best approach to manage diarrhea is to:

• Replace lost fluids by drinking water, oral rehydration solutions, or other fluids that contain electrolytes.
• Resume eating as soon as tolerated by choosing bland, easy-to-digest foods such as yogurt, bananas, oatmeal, rice, toast, crackers, potatoes, and soup.
• Avoid fatty, greasy, spicy, or high-sugar foods, as well as alcohol, until symptoms improve.
• Seek medical care if diarrhea lasts more than a few days, is accompanied by a high fever or bloody stools, or causes signs of dehydration.

Constipation 

Constipation

is defined as infrequent bowel movements (typically fewer than three per week) or stools that are hard, dry, or difficult to pass. It occurs when waste moves too slowly through the large intestine, allowing too much water to be absorbed from the stool. Constipation may result from a low-fiber diet, inadequate fluid intake, physical inactivity, certain medications, pregnancy, aging, travel, or changes in routine. Persistent constipation should be evaluated by a healthcare provider.

MANAGING CONSTIPATION

Most cases of constipation improve with healthy lifestyle habits:

• Eat more fiber-rich foods, including whole grains, fruits, vegetables, legumes, nuts, and seeds.
• Drink adequate fluids throughout the day.
• Engage in regular physical activity.
• Establish a regular bowel routine, such as attempting a bowel movement after meals.
• Fiber supplements (e.g., Metamucil, Citrucel, Benefiber) may provide short-term support when needed.
• Use laxatives only occasionally and under the guidance of a healthcare provider, as long-term use may lead to dependence. ^[2]

Irritable Bowel Syndrome 

Irritable bowel syndrome (IBS) is a common functional gastrointestinal (GI) disorder, meaning that the digestive tract appears normal but does not function properly. It is thought to result from abnormal communication between the brain and the gut. Approximately 12% of adults in the United States have IBS. It is more common in women, tends to run in families, and is associated with stress, a history of trauma, or previous gastrointestinal infections.

Common symptoms include abdominal pain, bloating, cramping, a feeling of incomplete bowel emptying, and changes in bowel habits, including diarrhea, constipation, or alternating episodes of both. Although IBS can significantly affect quality of life, it does not damage the digestive tract or increase the risk of colorectal cancer.

Managing irritable bowel syndrome

Because the exact cause of IBS is unknown, treatment focuses on managing symptoms. Strategies that may help include:

• Eat a healthy diet and identify foods that trigger symptoms.
• Increase dietary fiber gradually, especially for constipation-predominant IBS.
• Engage in regular physical activity.
• Manage stress through relaxation techniques, exercise, or counseling.
• Medications may be prescribed to relieve diarrhea, constipation, abdominal pain, or other symptoms when lifestyle changes alone are not effective.

Some people benefit from a low-FODMAP diet, which temporarily limits certain fermentable carbohydrates that are poorly absorbed in the small intestine.  ( FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols.) These carbohydrates can be fermented by bacteria in the large intestine, producing gas and drawing water into the intestine, which may trigger bloating, abdominal pain, diarrhea, or constipation in susceptible individuals. Because many healthy foods contain FODMAPs, this diet should be followed only under the guidance of a healthcare professional or registered dietitian. Foods are gradually reintroduced to identify which ones trigger symptoms.

INFLAMMATORY BOWEL DISEASE

Inflammatory bowel disease (IBD) is a group of chronic disorders characterized by inflammation and damage to the gastrointestinal (GI) tract. The two main forms are ulcerative colitis and Crohn’s disease. Ulcerative colitis affects only the large intestine (colon) and rectum, whereas Crohn’s disease can affect any part of the GI tract from the mouth to the anus. Symptoms often occur in cycles, with periods of remission followed by flare-ups.

IBD is often confused with irritable bowel syndrome (IBS) because of the similar names. However, they are very different conditions. IBS is a functional disorde that does not damage the digestive tract, whereas IBD is an inflammatory disease that causes visible injury to the intestinal lining and can lead to serious complications if left untreated.

Common symptoms of IBD include persistent diarrhea, abdominal pain and cramping, fatigue, weight loss, and sometimes blood in the stool. Although the exact cause is unknown, IBD is thought to result from an abnormal immune response in genetically susceptible individuals. It often develops during adolescence or early adulthood.

MANAGING INFLAMMATORY BOWEL DISEASE

Treatment focuses on reducing inflammation, controlling symptoms, and preventing complications. Depending on the type and severity of the disease, management may include:

• Medications that reduce inflammation or modify the immune system.
• Nutrition support to correct nutrient deficiencies and maintain adequate nutrition.
• Surgery to remove damaged portions of the digestive tract when medications are not effective or complications occur.

attributions

This section is an adaptation of “Disorders of the GI Tract” in Nutrition: Science and Everyday Applications, V.1.0 by Alice Callahan, Heather Leonard, and Tamberly Powell under a Creative Commons Attribution-NonCommercial 4.0 International License.