Table of content

• 8 important parts of GIT(Gastro-Intestinal Tract)

• What are the functions of the gastrointestinal tract?

• Disorders of the salivary glands

• 5 most common diseases of the esophagus

• 3 Common gastrointestinal diseases involving the stomach

• 4 Disorders of GIT involving the Intestines

• What tests will I need to diagnose gastrointestinal disorders?

• Treatment for gastrointestinal disorders

Introduction 

The full form of GIT in medical terms is ‘Gastro-Intestinal Tract ‘, also called an ‘alimentary tract’. The system of organs compromising the gastrointestinal tract and its associated organs is called the Gastrointestinal system or the digestive system. The gastrointestinal tract (GIT) acts as a doorway for all the nutrients and any disruption associated with the intake and metabolism of food, disorders of GIT and its accessory organs impact your overall health status greatly. 

8 important parts of GIT(Gastro-Intestinal Tract)

Before delving into the details of the common gastrointestinal diseases, it’s necessary to know what the GI system is made of. The various parts of GIT include:

1. Mouth.

2. Throat (pharynx).

3. Food pipe ( esophagus).

4. Stomach.

5. Small intestine (which has 3 consecutive parts namely duodenum, jejunum and ileum).

6. Large intestine.

7. Rectum and

8. Anus.

The major associated organs of the digestive system include: 

• Liver

• Gallbladder and

• Pancreas

So, basically the GI tract is a continuous pipeline of organs starting at the mouth and ending at the anus. Each of the above organs have specific functions in the process of digestion and metabolism of the food that is taken in.

What are the functions of the gastrointestinal tract?

To get a better understanding of the different types of gastrointestinal disorders, we need to first know about the normal functions of the GIT.

• Ingestion of food.

• Digestion of this food by the action of digestive juices and enzymes from different organs like salivary glands, stomach, gallbladder, pancreas etc.

• Absorption of nutrients from the digested food into the blood circulation.

• Excretion of waste products after digestion.

These are the overall functions of the gastrointestinal system as a whole.

Let’s take a quick look at the specific roles played by each of the organs in the GIT. 

Saliva

Salivary juices produced by different salivary glands contain enzymes that help in breaking down the carbohydrates and fats in your food into smaller pieces. So the process of digestion starts right in the mouth, which makes it important to chew the food properly.

Further saliva keeps the mouth moist, prevents tooth decay and helps in speech.

Pharynx

The swallowing mechanism of the pharynx ensures that food does not enter into the windpipe while swallowing, and goes straight into the food pipe.

Esophagus

It also called the food pipe, this helps in transmitting the food from the throat to the stomach.

Stomach

The stomach mixes and grinds the food into a liquid form called chyme. Further, the stomach acts like a storehouse of the food and releases it into the small intestine at a rate that the food can be further processed in the intestines. Various acids and gastric juices produced by the stomach facilitate digestion.

Small intestine

The small intestine is a key area for absorption of nutrients from the food. These nutrients include carbohydrates, fats, proteins, vitamins, minerals, and water.

Large intestine

After absorption of nutrients from the small intestine, the large intestine now turns all the food waste into solid stools that pass out of the body via the anus during defecation.

Liver and gallbladder

The main job of the liver in digestion is to detoxify and process the food. It also secretes bile which is stored in the gallbladder and released into the small intestine, which plays an important role in the digestion of fat and fat soluble vitamins. The liver also acts as a storehouse for surplus glucose.

Pancreas

This organ produces several important enzymes involved in the digestion of fats and carbohydrates and hormones

Now that we have a better understanding of how the different parts of the digestive system function together, let’s talk briefly about the common gastrointestinal diseases and the symptoms seen in the various gastrointestinal diseases.

Disorders of the salivary glands

There are 3 major salivary glands (parotid, submandibular and sublingual glands) and thousands of minor salivary glands in and around the mouth. They can be affected by a number of diseases like stone formation (called sialolithiasis), bacterial and viral infections (like mumps, influenza etc.,) inflammation (called sialadenitis), lack of salivary secretions leading to dry mouth (called Sjögren’s syndrome) and even cancerous conditions can arise in the salivary glands.

Symptoms: Patients with salivary gland disorders usually present with complaints like fever, foul breath due to pus formation, tooth decay, swollen glands, headache , difficulty in speaking and swallowing etc.,

Pharyngeal disorder

The pharynx is a hollow tubular organ that connects the mouth to the esophagus. Gastrointestinal disorders involving the pharynx can range from a mild sore throat to tonsillitis (inflammation of the tonsils, usually seen in children), infections like croup (seen in children causing a barking type of cough) or diphtheria (bacterial disease causing a patchy membrane formation over the throat, which could result in breathing difficulty in severe cases) and even cancer.

Patients suffering from pharyngeal diseases usually present with difficulty in swallowing or painful swallowing, coughing or white patches over the tonsils. In cancers of the pharynx, the patient would present with loss of weight, fatigue, swallowing difficulty and blood in vomit etc. 

5 most common diseases of the esophagus

There are several common gastrointestinal diseases involving the esophagus. These include:

1. Gastro Esophageal Reflux Disease (GERD)

GERD is one of the most common gastrointestinal diseases, seen in a large proportion of people. In GERD, the muscles at the lower end of the esophagus do not close completely, thereby leading to the acidic stomach contents reflux into the food pipe, thereby damaging it. If prolonged and uncorrected, this can lead to severe ulcers. 

2. Barrett’s disease

This occurs as a complication of long-standing GERD, where the natural quality of the esophagus is altered and can end up in esophageal cancer. So, Barrett’s disease can be considered as a ‘premalignant’ condition, meaning a condition that can lead to cancer if left uncorrected.

3. Achalasia cardia

This happens due to nerve damage in the esophagus, thereby making it difficult to push food from the esophagus into the stomach.

4. Motility disorders

These are disorders occurring because of neural and muscular imbalances in the esophagus, thereby affecting the way in which the esophagus moves. This may cause swallowing problems. 

5. Esophageal cancer

This is a common cancer seen as a part of gastrointestinal disorders. High risk factors include prolonged GERD, peptic ulcer, Barrett’s disease, smoking etc.,

Symptoms of esophageal diseases

Usually the patient experiences heartburn, upper back pain or chest pain, difficulty in swallowing or feeling like something is stuck in the throat or chest, breathing problems due to severe pain etc.,

3 Common gastrointestinal diseases involving the stomach

The stomach is a key organ of the GIT, hence there are plenty of gastrointestinal disorders seen involving this organ. 

1. Gastritis

Inflammation (swelling) of the mucosal lining of the stomach is called gastritis.

This can occur due to several factors like spicy diet, painkiller abuse like aspirin especially if taken without prescription, alcoholism, stressful lifestyle etc.,

2. Peptic Ulcers

An ulcer is a tear or break in the inner mucosal lining of the stomach or the duodenum. Common causes include bacterial invasion like Helicobacter pylori or because of chronic usage of painkillers belonging to a group called NSAIDs (non-steroidal anti-inflammatory drugs) like aspirin etc.

Typical gastrointestinal disorder symptoms like upper abdominal pain, vomiting and loss of appetite may be seen in peptic ulcers. Eating may cause pain as the food passes through the affected regions and the patient may start avoiding food for this reason. This may cause weight loss.

3. Gastric / stomach cancer

This is one of the most common gastrointestinal diseases amongst cancers of the human body. Cancers Can present with weight loss, fatigue and blood vomiting.

4 Disorders of GIT involving the Intestines

• Since the small intestine is concerned with absorption of nutrients from the food, gastrointestinal disorders affecting the small intestine present with general weakness of the body due to lack of nourishment.

• Gastrointestinal disorders involving the large intestine present with altered frequency and consistency of stools.

• Cancers involving any part of the intestines present with weight loss, abdominal pain, severe weakness, altered stool habits, blood in stools etc.,

Some common gastrointestinal diseases involving the intestines include:

1. Irritable Bowel syndrome ( IBS)

This is a functional disorder, meaning there are no structural abnormalities associated with the disease, rather it happens because or other factors like increased sensitivity of the intestinal nerves to any stimulus, genetics, infections, hormonal and psychological factors, stress etc., The patient suffers from pain, bloating sensation, altered bowel habits etc.,

2. Inflammatory bowel disease (IBD)

IBDs are common disorders of GIT in which there is an inflammation seen involving the different layers of the gastrointestinal tract.

There are 2 types of IBD

1. Crohn’s disease and Ulcerative colitis. Crohn’s can affect any part of the GIT, right from the mouth until the anus causing symptoms like fever, weight loss, nausea, mouth ulcers, anal fissures, vomiting, etc. Chronic watery diarrhea may also occur.

2. Ulcerative colitis predominantly affects the large intestine, especially the rectum. Major symptoms include abdominal pain, pus and mucus in stools, bloody diarrhea, anemia, and loss of appetite.

3. Diverticulosis

Diverticulosis is a gastrointestinal disorder characterized by the development of multiple small pouches (diverticulums) in the inner lining of the large intestine. Most people suffering from this disease do not show any symptoms, except in severe conditions where it could lead to obstruction of the intestine which could be life threatening. It’s usually seen in older adults.

When these pouches get infected and inflamed, it’s called diverticulitis which can present with high-grade fever and an excruciating pain in the lower abdomen, chills, nausea and vomiting. It can also lead to altered bowel habits like constipation or diarrhoea. Diverticulosis and diverticulitis are also common gastrointestinal diseases seen in a sizable proportion of people.

4. Colorectal cancers

These are one of the most common cancers of the human body, claiming thousands of lives every year around the world. These cancers usually begin as a small outgrowth (called a polyp) and later develop into extensive cancers.

What tests will I need to diagnose gastrointestinal disorders?

1. Barium studies

Barium is a radio-opaque substance, meaning if given inside the gastrointestinal tract and an X-ray is taken, it will help in understanding the structure and any abnormalities in the GIT. There are different types of barium studies like barium swallow (to study esophagus), barium meal (to study stomach and small intestine), barium enema (to study the large intestine) etc., it’s a basic diagnostic modality usually done in an empty stomach.

2. Scopes

There are different types of scopes, used to visualize different parts of the GIT, thereby helping to diagnose any gastrointestinal disorders. These include endoscopy (used to visualize the inside of esophagus, stomach and initial parts of the small intestine), colonoscopy (used to visualize the inside of the entire large intestine), sigmoidoscopy (used to visualize only part of the large intestine) etc., all of these scopes have a camera in the tip that helps to see real-time the issue inside the GIT and the surgeon may take biopsy bits from within your GIT if she/he suspects a cancer.

Nowadays, the latest technology is the use of a capsule endoscopy in which a camera is placed inside a capsule sized structure and the patient is made to swallow it. As it passes through his system, it takes photographs of the GIT.

3. ERCP

(Endoscopic Retrograde Cholangiopancreatography)! Do not let the huge name scare you! It’s a type of endoscope that helps in visualizing the pancreatic and bile duct system and it can also be used in treating the disorders in these parts.

4. Ultrasound studies CT and MRI scans

These imaging modalities are used in diagnosing different conditions of the gastrointestinal tract whenever basic diagnostic tests do not offer any clarity.

5. Manometer studies and PH studies

These studies are used in diagnosing esophageal diseases like GERD and achalasia. Manometer tells about the pressure changes in the lower esophageal and pH monitoring explains whether gastric acidic contents are refluxing into the esophagus.

There are plenty of other novel diagnostic modalities available for evaluating the gastrointestinal disorders, but these are the most commonly used.

Treatment for gastrointestinal disorders

Milder problems like indigestion can be treated with home remedies like good diet, adequate hydration and rest.

However, plenty of gastrointestinal disorders like peptic ulcer, GERD require sincere lifestyle modifications to be completely relieved of them. These include:

• Avoid spicy diets, high fat diets, and carbonated soft drinks

• Drink plenty of soft, oral fluids

• Avoid self-medication, especially with painkillers as they can harm your stomach lining

• Quit smoking and alcohol if you experience recurrent ulcers

• If you’re suffering from reflux and heartburn, avoid lying down immediately after eating. Sleep in a semi-sitting position at night.

You could also try to follow some tips to improve your digestion naturally.

Need for medical management

if you are experiencing any long-standing complaints with respect to the gastrointestinal system, it’s important to consult a doctor immediately. If the treating physician or surgeon deems it necessary, they may prescribe you drugs for a variety of complaints. These drugs could include antacids, drugs to reduce acid production, drugs to kill the bacteria causing peptic ulcer, drugs to treat diarrhoea or constipation, supplement drugs if the person is losing nutrients due to small intestinal diseases etc.,

Need for surgical management

Other than the mild gastrointestinal disorders that could be treated with drugs and lifestyle modifications, most of the severe and persistent complaints may need surgical correction or intervention to be completely relieved of them. This may especially hold good if any cancers of the gastrointestinal tract are diagnosed, needing extensive surgeries. This again depends exclusively on the patient and his current status. Cancers may also require radiotherapy and chemotherapy along with surgeries depending on the need.

Importance of screening in gastrointestinal disorders

Screening is a process by which constant monitoring is done in vulnerable populations even before the disease symptoms have begun. This may help to diagnose much earlier than usual, thereby improving the treatment options and life span of the person. In the GIT, screening holds special importance with respect to colorectal cancer. These cancers have a genetic background and usually begin as a polyp like outgrowth. By regular screening colonoscopy, if these polyps are picked up and can be removed before they become cancerous.

If you are experiencing complaints like blood in stools, weight loss, tiredness etc, or have someone affected with colorectal cancer in your family, get screened today .

Wishes for a happy and healthy life!

Reference:

1. NDDK