List of Common Gastrointestinal Diseases

A gastrointestinal disease, also known as a digestive disorder, is one that affects the gastrointestinal (GI) tract. This is the organ system that runs from the mouth to the anus and includes the pharynx (throat), esophagus (feeding tube), stomach, small intestine, large intestine (colon), and rectum.

GI diseases are broadly classified as being either functional, meaning that the digestive tract isn't functioning as it is supposed to, or structural, meaning that a physical abnormality in a digestive organ keeps it from functioning normally.

Examples of functional GI diseases include irritable bowel syndrome (IBS) and acid reflux, while examples of structural GI diseases include hemorrhoids, diverticulosis, and colon cancer.

As many as 11% of Americans have a gastrointestinal disease. Some can disrupt the normal absorption of nutrients in food and cause significant distress and disability. Others may require aggressive treatments or surgery to avoid serious illness or death.

Functional GI Diseases

Functional GI diseases are characterized by chronic (persistent or recurring) symptoms like pain and bloating that arise due to the dysfunction of the digestive tract. These symptoms occur despite there being no evidence of a structural abnormality or disease.

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic condition affecting the large intestine. IBS causes abdominal pain, gas, bloating, diarrhea, and/or constipation. The cause of this functional disorder is unknown A diagnosis is made based on symptoms alone.

There are three types of IBS, characterized by whether they mainly cause constipation, diarrhea, or recurring episodes of both:

• Constipation predominant IBS (IBS-C)
• Diarrhea predominant IBS (IBS-D)
• IBS mixed types (IBS-M)

Although IBS can impact a person’s quality of life, it neither increases the risk of other GI diseases nor causes any permanent damage to the GI tract.

Roughly 10% to 15% of people in the United States experience IBS symptoms, with only around half obtaining an official diagnosis and treatment.

Functional Dyspepsia

Functional dyspepsia is characterized by chronic symptoms of indigestion without an underlying cause. Functional dyspepsia often resembles symptoms of a peptic ulcer but without any evidence of tissue damage or sores.

Symptoms of functional dyspepsia include:

• Upset stomach
• Bloating
• Excessive belching
• Nausea or vomiting after eating
• Early satiation (feeling full after eating only a small amount of food)
• Heartburn
• Acid reflux

Between 10% to 20% of people who seek treatment for chronic indigestion are diagnosed with functional dyspepsia. As with IBS, functional dyspepsia is diagnosed based on the symptoms and the absence of any other medical explanation.

Dyssynergic Defecation

Dyssynergic defecation (DD) is a chronic condition that makes it difficult to pass stools due to the dysfunction of muscles and nerves in the pelvic floor. DD commonly presents with chronic constipation and other symptoms, like:

• Hardened, pebbly stools
• Less than three bowel movements per week
• Prolonged sitting on the toilet
• Abdominal pain
• Gas and bloating
• Excessive straining
• Tenesmus (a feeling that your bowel is never empty)
• Hemorrhoids

DD usually starts in early childhood and persists into adulthood. It is a relatively common disorder thought to account for 15% to 25% of all chronic constipation cases.

Levator Ani Syndrome

Levator ani syndrome (LAS) is a chronic condition affecting the pelvic floor muscles that cause rectal or vaginal pain. The pain—caused by spasms of the levator ani muscles situated near the anus—is typically dull but deeply felt, lasting anywhere from a few minutes to hours.

In addition to symptoms of pain, burning, and pressure, LAS can also cause:

• Painful or difficult bowel movements
• Frequent bowel movements
• Urinary urgency (the feeling you need to pee all the time)
• Loss of bladder or bowel control
• Pain with sex

LAS is thought to affect 7.4% of females and 5.7% of males, typically between the ages of 30 and 60.

Cyclic Vomiting Syndrome

Cyclic vomiting syndrome (CVS) is a chronic condition of unknown origin that causes recurrent episodes of vomiting. CVS can affect people of any age but predominately affects children.

CVS is considered cyclic because it occurs in four repetitive stages:

• Inter-episodic phase: A period lasting a week to a month or more during which there are no symptoms
• Prodromal phase: A period lasting one to several days where belching and upset stomach start to develop
• Emetic phase: A period of intense persistent nausea and repeated vomiting, lasting a few hours to several days or longer
• Recovery phase: A period lasting several days where vomiting ceases, nausea subsides, and appetite returns

CVS is a rare condition that typically starts in childhood. Studies suggest that as few as four of every 100,000 school-aged children are affected. Many children with CVS outgrow the condition, while others don't.

Other Functional GI Disorders

Any GI disorder that occurs for no structural reason and in the absence of a diagnosable disease can be regarded as functional. These include common and uncommon conditions such as:

• Functional dysphagia (difficulty swallowing)
• Functional diarrhea
• Functional bloating
• Belching disorders
• Functional biliary pain
• Functional fecal incontinence (loss of bowel control)

In some cases, a condition classified as functional may later be found to have an organic cause. It is only when all possible causes have been excluded that a GI disease can be confidently diagnosed as being functional.

Structural GI Diseases

Structural GI diseases occur because there is a change or problem within the structure of the GI tract. These structural issues can occur anywhere in the GI tract and either be acute (sudden and short-lasting) or chronic.

GERD

Acid reflux is the backflow of stomach acid into the esophagus and throat. When the condition becomes chronic, it is referred to as gastroesophageal reflux disease (GERD).

GERD occurs when the muscular valve separating the stomach from the esophagus, called the lower esophageal sphincter (LES), either becomes weak or relaxes when it is not supposed to. This allows stomach acid to backflow (reflux) into the esophagus.

Symptoms of acid reflux include:

• Heartburn
• Regurgitation
• A burning sensation in the middle of the chest
• A bitter mouth taste
• Nausea
• Difficulty swallowing
• Chronic cough
• Hoarseness

Left untreated, GERD can lead to esophageal bleeding, esophageal stricture (narrowing of the esophagus), and esophageal damage (referred to as Barrett's esophagus).

An estimated 20% of adults and up to 40% of children experience symptoms of GERD at some point in their lives.

Hemorrhoids

Hemorrhoids are swollen or inflamed blood vessels in or around the anus. They develop when there is increased pressure on these veins. They can occur both internally and externally.

Common symptoms of hemorrhoids include:

• Bright red blood on toilet paper, in the toilet, or in your stool
• Anal pain or irritation, particularly during bowel movements
• A hard lump or swelling around the anus
• Rectal itching

Roughly 50% of people over the age of 50 have hemorrhoids. People at increased risk are those who eat a low-fiber diet, have chronic diarrhea or constipation, are pregnant, have obesity, or regularly lift heavy objects (like furniture movers).

Diverticulosis

Diverticulosis is a condition that develops when bulging pouches, known as diverticula, form in the lining of the digestive tract. In some cases, diverticulosis can progress to diverticulitis in which the pouches become inflamed due to an infection.

While most people with diverticulosis have no symptoms, those who develop diverticulitis commonly experience:

• Pain in the lower left abdomen
• Constipation or diarrhea
• Fever
• Chills
• Nausea and vomiting

It is estimated that 50% of people over the age of 60 and 70% over the age of 80 have diverticulosis. Of these, roughly one in six will go on to develop diverticulitis.

Risk factors for diverticulosis and diverticulitis include obesity, diabetes, heavy alcohol use, smoking, and a high consumption of red meat.

Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an immune-related disorder that causes inflammation and progressive damage to the GI tract. There are two forms of IBD, characterized in part by their location in the digestive tract:

• Crohn's disease (CD): Occurring anywhere between the mouth and the anus, often with a mix of normal and inflamed tissues
• Ulcerative colitis (UC): Limited to the main part of the large intestine, called the colon, with continuous inflammation throughout

Symptoms include abdominal pain, cramping, fatigue, diarrhea, fever, mucus or blood in stool, and the urgent need to go to the bathroom frequently.

Left untreated, IBD can lead to complications like bowel obstruction, bowel perforation, anemia (due to blood loss), and an increased risk of colon cancer.

IBD is thought to affect 1.2 million adults and 58,000 children in the United States. UC tends to start in a person's 20s and 30s, while CD often starts during the teen years. Genetics are thought to play a central role in both diseases.

Colitis

Colitis is inflammation of the colon. Ulcerative colitis (UC) is one of the most well-known types of colitis, but there are several others, including:

• Microscopic colitis: Caused by microscopic changes to the colon, often due to the excessive production of immune cells or collagen that stress intestinal tissues
• Allergic colitis: A condition typically seen in newborns and infants that is thought to be linked to a breast milk allergy
• Ischemic colitis: Caused when blood flow to the colon is cut off or restricted, leading to intestinal inflammation and necrosis (tissue death)
• Infectious colitis: Caused when a bacteria known as Clostridioides difficile overgrows in the intestine, often as a result of heavy antibiotic use

Common symptoms of colitis include abdominal pain, cramps, bloating, bloody stool, nausea, vomiting, and an urgent need to empty the bowels.

Perianal Abscesses and Fistulas

A perianal abscess is a pocket of pus that develops in the skin surrounding the anus. It is typically caused when a break in the skin allows bacteria to enter underlying tissues and establish an infection.

Symptoms of a perianal abscess include:

• A palpable bump on the surface of the skin
• Redness and swelling
• Tenderness to the touch
• Itching or burning sensation
• Pain when having a bowel movement

Left untreated, an abscess can lead to the development of an anal fistula (an abnormal passage between tissues). Fistulas typically require surgical repair.

About 90% of perianal abscesses occur due to blockage or infection of anal glands. IBD is a common cause. People with diabetes or immune suppression, like HIV, also may be at higher risk.

Anal Fissures

Anal fissures are small tears in the thin and moist tissue that lines the anus, known as mucous membranes. They occur when the mucosa becomes stretched beyond its capacity and tears, often due to hard stool.

Symptoms of anal fissures:

• Pain during or after having a bowel movement
• Visible cuts or tears in the anal area
• Bright red blood during or following a bowel movement

Anal fissures are most common in people with chronic constipation. It can also develop in someone who has chronic diarrhea, has undergone rectal surgery, or engages in anal sex. Up to 20% of people with hemorrhoids also have anal fissures.

In some cases, anal fissures can last up to eight to 12 weeks before healing.

Colon Cancer

Colon polyps are abnormal clumps of cells that form a mass inside the colon. While most colon polyps are harmless, some can turn into colon cancer within 10 to 20 years. The exact cause of these growths isn’t known but factors like a poor diet, obesity, and smoking play a part.

Most colon polyps don’t cause symptoms. It is only when they grow to a significant size—most often when a benign growth turns cancerous—that symptoms can develop, including:

• Changes in bowel habits
• Narrowing of the stool
• Diarrhea or constipation
• Tenesmus
  
• Rectal bleeding
• Bloody stool
• Cramping
• Abdominal pain
• Weakness and fatigue
• Unexplained weight loss

Different types of polyps are more likely to turn cancerous, including adenomatous polyps that are often flat and hard to identify and remove. Roughly 14% of adenomatous polyps will develop into cancer after 10 years.

Colon cancer—more appropriately referred to as colorectal cancer—is the fourth most common cancer in the United States. The lifetime risk of developing colorectal cancer is about one in 23 for males and one in 25 for females.

How GI Diseases Are Diagnosed

Diagnosing and treating gastrointestinal disease will vary widely depending on the type, cause, and severity of the condition. These are commonly diagnosed by a specialist in the GI tract known as a gastroenterologist.

When it comes to diagnosing these conditions, your healthcare provider will gather your health history, lifestyle habits, and symptoms to determine what tests are needed to further investigate the issue.

Several tests may be used to diagnose a GI condition, including:

• Colonoscopy
• Upper GI endoscopy
• Capsule endoscopy
• Endoscopic retrograde cholangiopancreatography (ERCP)
• Endoscopic ultrasound

The treatment can differ based on the diagnosis. In some cases, changing your diet and lifestyle habits may provide ample relief. If diet and lifestyle changes aren’t enough, your healthcare provider may prescribe medications or order surgery or other specialist procedures to treat or manage the underlying cause.

Preventing Gastrointestinal Disease

While not all GI diseases can be prevented, the best way to keep them at bay is by living a healthy lifestyle. This includes:

• Eating a healthy diet with fruits, vegetables, and the proper amount of fiber
• Getting quality sleep
• Staying hydrated by drinking enough water

High levels of stress may also be associated with the onset of certain GI diseases, so limiting stress whenever possible and practicing stress-reduction techniques may be helpful in preventing digestive diseases.

Physical activity, specifically light physical activity, has also been shown to improve GI disease symptoms in some people.

Summary

There are many different GI diseases classified as being either functional or structural.

Functional GI disorders like IBS, GERD, and functional dyspepsia occur in the absence of a structural problem or diagnosable disease. Structural GI disorders like hemorrhoids, diverticulosis, and colon cancer have a known cause that disrupts the normal function of the digestive tract.

The diagnosis of a functional or structural GI disease typically involves a gastroenterologist who can order different tests and procedures to investigate the most likely causes.

A Word From Verywell

The challenges of living with a gastrointestinal disorder are constant and sometimes overwhelming. Seeking the care of a gastroenterologist or gastrointestinal specialist is essential for confirming a diagnosis and developing and following the right treatment plan.

— JAY N. YEPURI, MD, MEDICAL EXPERT BOARD