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Gastrointestinal (GI) diseases is the term used to refer to any condition or disease that occurs within the gastrointestinal tract.

A number of different conditions or diseases can affect the GI tract and have an impact on digestion and our overall health. According to the National Institute of Diabetes and Digestive and Kidney Diseases, somewhere between 60 million and 70 million Americans suffer from gastrointestinal problems.

In this blog, we will lay out exactly what gastrointestinal diseases are, factors that affect the GI tract, causes and GI symptoms, and the most common diseases.

  1. What are gastrointestinal diseases?
  2. What causes gastrointestinal disease?

  3. Gastrointestinal Disease Symptoms
  4. Types of Gastrointestinal Diseases
  5. Common Gastrointestinal Diseases
  6. How to Treat Gastrointestinal Disease

Please consult with your physician for the best treatment course for you.

Gastroenterology Specialty Pharmacy | Senderra

What are gastrointestinal diseases?

Gastrointestinal diseases affect the GI tract, including the mouth, salivary glands, throat, esophagus, stomach, small and large intestines, liver, gall bladder, pancreas, rectum and anus.

The GI tract is made of a series of organs that form the continuous passage from our mouth to our anus. The organs that make up our gastrointestinal tract are our mouth, esophagus, stomach, small intestine, large intestine and anus. Our GI tract, together with our liver, pancreas, and gallbladder, make up our digestive system.

Acute, short-term gastrointestinal illnesses include viral gastroenteritis (stomach flu), food poisoning, and other gastrointestinal infections such as diarrhea, vomiting, and abdominal discomfort.

What causes gastrointestinal disease?

Causes of digestive disorders vary, however, common causes include:

  • Aging
  • Consuming a lot of dairy / lactose intolerance
  • Genetics
  • Inactive lifestyle
  • A low fiber diet‍
  • Stress (learn more about reducing workplace stress)
  • Not drinking enough water

Many factors may upset your GI tract and its motility, including:

  • Eating low fiber diet
  • Not getting enough exercise
  • Traveling or changes in routine
  • Eating large amounts of dairy products / lactose intolerance
  • Stress
  • Resisting the urge to have a bowel movement
  • Overusing anti-diarrheal medications
  • Pregnancy
  • Taking antacid medicines containing calcium or aluminum
  • Taking certain medicines (antidepressants, iron pills and strong pain medication)

Gastrointestinal Disease Symptoms

Symptoms of digestive disorders vary by each person's condition. However, some symptoms are more common to gastrointestinal illnesses. These common GI symptoms include:

Types of Gastrointestinal Diseases

There are two types of GI diseases: functional and structural.

1. Functional Gastrointestinal Diseases

Functional gastrointestinal diseases are those in which the GI tract looks normal when examined, but doesn't move properly. They are the most common problems affecting the gastrointestinal tract. Constipation, irritable bowel syndrome (IBS), nausea, food poisoning, gas, bloating, gastroesophageal reflux disease (GERD) and diarrhea are common examples.

2. Structural Gastrointestinal Diseases

Structural gastrointestinal diseases are those where your bowel looks abnormal upon examination and also doesn't work properly. Sometimes, the structural abnormality needs to be removed surgically. Common examples of structural GI diseases include strictures, stenosis, hemorrhoids, diverticular disease, colon polyps, colon cancer and inflammatory bowel disease.

GI Immunology Support

Common Gastrointestinal Diseases

(Click below to jump to section.)

Celiac Disease

Celiac disease is a multifactorial gastrointestinal disorder, meaning it is triggered by factors in the environment. Celiac is caused by an autoimmune reaction to gluten which destroys villi, small hair-like projections on the lining of the small bowel. When the villi are destroyed, the small intestine is unable to effectively absorb nutrients, vitamins, and minerals from food. This results in malnutrition and can lead to many serious health problems, including infertility, permanent damage to the small bowel, and even the big “c” - intestinal lymphoma.

Crohn’s Disease

Crohn’s disease is a chronic inflammatory digestive disease that can affect any part of the GI tract, from the mouth to the anus. It most commonly however involves the ileum (the lower side of the small bowel) that becomes ulcerated and inflamed. Along with ulcerative colitis, this condition is part of a group of gastrointestinal disorders called inflammatory bowel disease (IBD). Crohn’s disease is most often diagnosed in those aged between 15 and 30, although it can develop at any age. According to the Crohn’s & Colitis Foundation, around 780,000 individuals in the U.S. have Crohn’s disease.


The condition diverticulosis is characterized by the formation of small pockets or pouches called diverticula in the lower part of the inner lining of the colon (the large intestine). Diverticulitis refers to the inflammation of these pockets, that become swollen with waste and get infected. This can lead to a range of mild to serious complications, including rectal bleeding. Diverticulitis occurs in severe or advanced diverticulosis.

Gastroesophageal Reflux Disease (GERD)

Gastroesophageal reflux disease (GERD) is defined as having GI symptoms of acid reflux twice or more times a week. Acid reflux or heartburn occurs when stomach contents and acids spill over into your esophagus, causing a burning sensation and chest pain. If not treated early, frequent bouts of heartburn can damage the esophagus. GERD usually manifests itself as a dry cough, discomfort in the chest area, sore throat, swallowing difficulties and sour taste in the back of the mouth.

Hepatitis C

Hepatitis C is a viral infection that causes liver inflammation, sometimes leading to serious liver damage. The Hepatitis C virus (HCV) spreads through contaminated blood. For some, Hepatitis C is a short-term illness, however, for more than half of people who become infected the virus is a long lasting infection. People with chronic Hepatitis C can sometimes have symptoms that takes decades to appear, resulting in people with HCV not knowing they're infected. When symptoms do appear, they are often a sign of advanced liver disease.

Irritable Bowel Syndrome (IBS)

Irritable Bowel Syndrome (IBS) is a group of gastrointestinal conditions where a combination of frequent abdominal pain, bloating and cramps is associated with either diarrhea or constipation. This occurs by any underlying inflammation, chemical or anatomical abnormalities, and is caused by a variety of factors, including irritated gut microbiota. Contrary to common misconception, this condition is not the same as Inflammatory Bowel Disease (IBD), a set of digestive disorders including ulcerative colitis and Crohn’s disease that cause inflammation of various parts of the GI tract. Some of the risk factors include being stressed and consumption of certain medicines and foods. Women are more susceptible to IBS more than men.

Liver Disease

The liver is the second largest organ and plays a varied role in digestion, including breaking down of food, storing energy, and getting rid of waste and toxins from the bloodstream. Liver disease is a collective term for all digestive conditions that affect the liver. While the causes may be different, they can all damage your liver and affect its function.

Gastrointestinal Lyme Disease

Lyme disease is caused by bacteria (Borrelia burgdorferi) and is transmitted to humans through the bite of infected ticks. Lyme disease is diagnosed based on symptoms, physical findings on your body, and the possibility of exposure to infected ticks. Although not considered gastroenterology, gastrointestinal manifestations can take place.

Lyme disease can cause GI symptoms such as nausea, vomiting, heartburn, constipation, gas and bloating. In chronic or late-stage Lyme disease abdominal pain and abdominal discomfort occur.

How to treat gastrointestinal Lyme disease? Several antibiotics, including doxycycline, amoxicillin, and cefuroxime, have been reported as effective treatments for Lyme disease, depending on the stage and which parts of the body are affected.

Ulcerative Colitis

Ulcerative colitis is one of the two most common inflammatory bowel diseases (IBD), along with Crohn’s disease. This diagnosis refers to a group of digestive disorders that cause inflammation of the GI tract. Ulcerative colitis is caused by the inflammation of the inner lining of the colon (large intestine), rectum or both.

How to Treat Gastrointestinal Disease

For general care of stomach and digestive issues, you can try drinking plenty of fluids, adding folic acid to your drip IV therapy, BRAT diet (bananas, rice, applesauce, and toast), and try to avoid dairy, grease and spices that bother your digestive system. Medications can also be prescribed to ease symptoms, such as nausea, to provide comfort and aid in the ability to rehydrate. Try using anti-nausea medications and/ or IV hydration. Learn more about gut health here.

For chronic conditions, reach out to your medical provider for an examination. Ask your doctor about gastrointestinal disease treatment and specialty pharmacies for gastrointestinal chronic diseases. Learn more about the 5 key factors to consider when selecting a specialty pharmacy.

As a Gastroenterology-focused Specialty Pharmacy, our pharmacists are trained to supervise the prescribed drug therapies for Gastroenterology patients. At Senderra, we understand the difficulty associated with managing the complex treatment plans and medications required for gastroenterological conditions such as Crohn’s and ulcerative colitis.

Learn more about Senderra Specialty Pharmacy for Gastroenterology for gastrointestinal disease treatment.

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Senderra-Logo_Mark-Only_COLOR-1Senderra is a national specialty pharmacy, serving patients with challenging and ongoing medical conditions through provision of specialty medicationsclinical expertise and support services.

We dedicate ourselves to designing and executing a model to serve the needs of our patients and partners (PrescribersPharma and Payers) in order to make a difference and effect positive outcomes.


No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. 

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