Pylorus: What is it? Structure, Function, Related Diseases, Causes, Diagnosis and Treatment

It is a muscular valve located between the stomach and the small intestine. It is the point of exit of the stomach and the entrance door to the duodenum of the small intestine.

It helps the stomach to contain food, liquids, acids, and other matters until they are ready to go to the small intestine, and then they are digested and then absorbed.

The Pylorus or pyloric part connects the stomach and the duodenum. The Pelorus has two parts, the pyloric antrum (which opens to the body of the stomach and the pyloric channel) that extends to the duodenum.

The pyloric duct ends like the pyloric orifice, marking the stomach and the duodenum junction. A sphincter surrounds the orifice; a muscle band called a pyloric sphincter.

Structure of Píloro

The Pylorus is the most extreme part of the stomach that connects to the duodenum. It is divided into two parts, the antrum, which connects to the body of the stomach, and the pyloric channel, which connects to the duodenum.

Pylorus cavity:

The pyloric antrum is the part of the Pylorus at the beginning. It is near the bottom of the stomach, on the other side of the pyloric sphincter, which separates the stomach and the duodenum.

It may temporarily be partially or wholly cut off from the rest of the stomach during digestion by peristaltic contraction of the prepyloric sphincter. It may be restricted from the pyloric channel with a slight groove.


Histology of Pylorus

If you look under microscopes, in the Pylorus, you can see numerous glands, including the gastric pits, forming approximately half the pyloric mucosa depth.

They consist of several short, closed tubes that open to a common conduit. These tubes are corrugated and have approximately half the length of the line.

The duct is lined by columnar cells and continues with the epithelium lining the surface of the mucous membrane of the stomach, the tubes with shorter and more cubic cells that are finely granular. The glands contain mucous cells and G cells that secrete the hormone gastrin.

Pylorus also contains parietal cells and neuroendocrine cells. These endocrine cells include D cells, which release somatostatin, the hormone responsible for closing acid secretion.

Pillar function

Pylorus is one of the components of the gastrointestinal system. Food from the stomach passes through the Pylorus to the duodenum. The Pylorus, through its pyloric sphincter, regulates the entry of food from the stomach into the duodenum.

For not entirely understood reasons, the Pylorus can sometimes thicken and cause luminal narrowing. This is called pyloric stenosis. This thickening can become so large that it blocks the flow of food from the stomach to the small intestine.

Diseases related to Pylorus


Pyloric stenosis is a rare condition in babies that prevents food from entering the small intestine.

Pyloric stenosis refers to a Pylorus that is narrow. This is happening due to congenital hypertrophy of the pyloric sphincter. The size of Píloro is more limited, and less food can pass.

Pyloric stenosis is more likely to affect tiny babies. It is found in 2 to 3 of every 1,000 babies.

This problem is often detected in the first weeks of life; it usually appears in the first 2 to 8 weeks; although it can occur in babies up to 6 months, pyloric stenosis is rare in babies older than three months.

The condition interferes with feeding, so it can affect growth and hydration. That is why early diagnosis and treatment are essential.

When present, a baby may vomit after eating but, despite vomiting, remains hungry.

Pyloric stenosis can be treated by inserting a stent or surgically cutting the pyloric sphincter. Pyloric stenosis can cause intense vomiting, dehydration, and weight loss.

Signs and symptoms of pyloric stenosis include:

Gastrointestinal problems are the main symptoms of pyloric stenosis. Most babies with this condition seem to be fine at birth. Symptoms usually begin and progressively get worse during the first months of life.

Symptoms may include:

Vomiting: intense vomiting after a feeding that differs from average regurgitation. As the pyloric valve thickens with time, vomiting becomes more frequent and explosive.

One of the first signs of pyloric stenosis is vomiting. At first, it may seem that the baby simply vomits often but then tends to turn into projectile vomiting, in which the food is expelled forcefully from the mouth, in an arch, sometimes at a great distance.

Vomiting projectile, which travels several feet from the baby’s mouth. They usually occur shortly after the end of a feeding.

The vomited food does not contain bile, a greenish liquid of the liver that mixes with the digested food after it leaves the stomach but still stinks.

Dehydration: the thickened Pylorus blocks the passage of solid foods and liquids. A dehydrated baby can cry without tears, have fewer wet diapers, and remain apathetic.

Dehydrated babies are less active than usual and may develop soft spots sunken in their heads and sunken eyes, and their skin may appear wrinkled. Because less pee is done, they can spend more hours with dry ladles.

You may find yourself changing less wet diapers or diapers that are not as wet as you expect.

Hunger: a baby with pyloric stenosis may want to feed constantly or be restless due to starvation.

Constipation: without adequate food and fluids that reach the intestines, the condition can cause constipation.

The baby will have fewer and smaller bowel movements due to little or no food that reaches the intestines. Constipation is also frequent. The third symptom is the inability to gain weight or lose weight.

Stomach cramps: Some parents notice “wavy” contractions that move through their baby’s abdomen after feeding. This occurs when the stomach muscles struggle to move the food through the narrowed pyloric lumen and the pyloric sphincter.

as of peristalsis:  occur after meals. They represent an increase in stomach contractions that can make perceptible waves that move from left to right over the belly of the baby while trying empty the stomach against thickened Pylorus.

Stomach Contractions: You may notice wavy contractions (peristalsis) that extend along your baby’s upper abdomen shortly after feeding but before vomiting. This is caused by stomach muscles trying to force food through the narrowed Pylorus.

Unlike a stomach infection, babies with pyloric stenosis usually do not appear sick between meals.

When to see a doctor

Consult your baby’s doctor if your baby:

  • He vomits in the form of a projectile after feeding.
  • It seems less active or unusually irritable.
  • Urinates much less often or has fewer bowel movements.
  • You are not gaining weight, or you are losing weight.

Causes of pyloric stenosis

The origins of pyloric stenosis are unknown, but genetic and circumstantial agents could play a role. Pyloric stenosis is not usually present at birth and probably develops later.

Pyloric stenosis is diagnosed by a detailed questionnaire about the baby’s diet and the doctors’ vomiting patterns. The doctor will look for a lump in the abdomen, usually firm and mobile.

If the doctor feels this lump, that is a strong indication that a baby has pyloric stenosis. Pyloric stenosis is seen more frequently in children, especially firstborns, than in girls.

When pyloric stenosis is suspected, an abdominal ultrasound is usually performed. The swollen Pylorus can be seen on ultrasound images.

Risk factor’s

Pyloric stenosis is not usual. Sure, babies are more prone than others. The things that put a baby at risk are:

Sex: male babies, especially firstborns, are more at risk than women.

Family history: Approximately 15 percent of babies with this condition have a family history of the disorder. A baby born to a woman with a baby status is three times more likely to have pyloric stenosis.

Race: the condition is more likely to affect Caucasians of descent from northern Europe. It is less common in African-Americans and Asians.

Smoking cigarettes: Smoking during pregnancy almost doubles the chance of giving birth to a baby with pyloric stenosis.

Bottle feeding: in a 2012 study, bottle-fed babies had a higher risk of pyloric stenosis, at least four times more likely to develop the condition than those who did not receive a bottle.

The experts in this study could not determine precisely whether the increased risk was due to the feeding mechanism itself or whether breast milk versus formula during feeding also contributed to the increased risk.

Use of antibiotics: Certain antibiotics early in life may increase the baby’s risk of pyloric stenosis. One study suggests that babies who received antibiotics in the first two weeks of life had the highest chance.

Diagnosis of pyloric stenosis

When pyloric stenosis is suspected, your baby’s doctor will perform a complete history and physical examination of your child’s abdomen. Sometimes the doctor may feel an olive-shaped lump, the enlarged pyloric muscle, when examining the baby’s abdomen.

If the doctor can feel a thickened pyloric muscle, which may look like an olive, you may not need further tests.

If the doctor can not feel the Pylorus, you may request an abdominal ultrasound to examine the abdominal tissue to see the Pylorus.

The doctor may also want to get x-ray images after your baby drinks a contrast liquid to help improve the clarity of the pictures.

This x-ray with oral contrast can show how the fluid travels from the stomach to the small intestine and shows if there is a blockage.

Surgery for Pylorus

Pyloric stenosis needs to be treated. It will not improve alone.

Your child will need a surgery called pyloromyotomy. During this surgery, which can be performed laparoscopically, a surgeon will cut part of the thickened muscle to restore the passage of food and fluids.

Suppose your baby is dehydrated due to frequent, heavy vomiting. In that case, you may need to be hospitalized and given fluid through an intravenous needle inserted into a vein (IV fluid) before surgery.

Once properly hydrated, your baby should refrain from feeding for several hours to reduce the risk of vomiting while under anesthesia.

The surgery takes less than an hour, but your baby will likely stay in the hospital for 24 to 36 hours. Most babies do well after surgery.

Shots are resumed gradually, and pain is usually treated with over-the-counter pain relievers.

It is usual for babies to vomit a bit in the first hours and days after surgery as the stomach calms down.

This condition can affect your child’s nutritional and hydration needs, so it is essential to seek medical help whenever you have difficulty feeding. The condition can be successfully corrected with surgery, and most babies will grow and thrive like other babies.


Pyloroplasty is a surgery to widen the Pylorus. This is an opening near the end of the stomach that allows food to flow into the duodenum, the first part of the small intestine.

The Pylorus is surrounded by a pyloric sphincter, a thick band of smooth muscle that causes it to open and close at certain stages of digestion.

Pylorus usually narrows to approximately 1 inch in diameter. When the pyloric opening is unusually narrow or blocked, it is difficult for food to pass. This leads to symptoms such as indigestion and constipation.

The pyloroplasty consists of cutting and removing part of the pyloric sphincter to widen and relax the Pylorus. This provides for the food to enter the duodenum. In some cases, the pyloric sphincter is wholly eliminated.

In addition to widening an exceedingly narrow Pylorus, pyloroplasty can also help treat various conditions affecting the stomach and gastrointestinal nerves, such as:

  • Pyloric stenosis is an abnormal narrowing of the Pylorus.
  • Pyloric atresia is a closed or absent pylorus at birth.
  • Peptic ulcers (open sores).
  • Parkinson’s disease
  • Multiple sclerosis.
  • Gastroparesis or delay in emptying the stomach.
  • Damage or infection of the vagus nerve.
  • Diabetes.

Depending on the condition, pyloroplasty can be done at the same time as another procedure, such as:

Vagotomy: this procedure involves the removal of certain branches of the vagus nerve, which controls the gastrointestinal organs.

Gastroduodenostomy: this procedure creates a new connection between the stomach and the duodenum.

How is it done?

Pyloroplasty can be performed as traditional open surgery. However, many doctors now offer laparoscopic options. These are minimally invasive and carry fewer risks.

Both types of surgery are usually performed under general anesthesia. This means you will be dozed off and not feel any pain during surgery.

How is the recovery?

Recovering from pyloroplasty is quite fast. Most people can begin to move or walk smoothly within 12 hours after surgery.

Many go home after approximately three days of monitoring and medical care. The more complex pyloroplasty surgeries may require a few extra days in the hospital.

While you recover, you may need to follow a restricted diet for a few weeks or months, depending on the extent of the surgery and the underlying medical conditions you have.

Keep in mind that it may take three months or more to see the full benefits of pyloroplasty.

Most people can resume non-strenuous exercise four to six weeks after the procedure.

Is there any risk?

All surgeries carry general risks. Some of the common complications associated with abdominal surgery include:

  • Stomach or intestinal damage.
  • Allergic reaction to anesthesia medications.
  • Internal bleeding.
  • Blood clots.
  • Scars.
  • Infection.
  • Hernia.

Empty the stomach:  Pyloroplasty can also cause rapid gastric emptying or stomach discharge. This means that the stomach contents empty into the small intestine too quickly.

When a stomach discharge occurs, food is not digested correctly when it reaches the intestines. This forces your organs to produce more digestive secretions than usual.

An enlarged Pylorus can also allow intestinal digestive fluids or bile to leak into the stomach. This can cause gastroenteritis. Over time, it can also lead to malnutrition in severe cases.

The symptoms of stomach discharge often start between 30 minutes and one hour after eating. Common symptoms include:

  • Abdominal cramps.
  • Diarrhea.
  • Swelling.
  • Nausea.
  • Vomiting is usually a greenish-yellowish liquid with a bitter taste.
  • Dizziness.
  • Rapid heart rate
  • Dehydration.
  • Exhaustion.

After a few hours, especially after eating sugary foods, the main symptom of the stomach discharge becomes a low blood sugar level.

It occurs because your body releases a large amount of insulin to digest as much sugar in the small intestine.

Symptoms of late stomach discharge include:

  • Exhaustion.
  • Dizziness
  • Rapid heart rate
  • General weakness
  • Perspiration.
  • Intense hunger is often painful.
  • Sickness.

Pyloroplasty is a type of intervention that enlarges the aperture in the lower part of the stomach. It is often used to treat gastrointestinal conditions that have not responded to other treatments.

It can be done using traditional methods of open surgery or laparoscopic techniques. After the procedure, you should be able to go home in a few days. It may take several months before you begin to notice the results.

Pylori Infections

H. pylori often infects your stomach during childhood. Although infections with this variety of bacteria usually do not cause symptoms, they can cause illness in some people, such as peptic ulcers and an inflammatory condition inside the stomach known as gastritis.

It is not yet known precisely how H. pylori infections spread. Bacteria have coexisted with humans for many thousands of years. It is believed that diseases spread from one person’s mouth to another.

They can also be transferred from the stool to the mouth. This can happen when a person does not wash their hands well after using the bathroom. H. pylori can also be spread by contact with contaminated water or food.

When the infection produces an ulcer, the symptoms may include abdominal pain, especially when the stomach is empty at night or a few hours after meals.

Pain is usually described as a throbbing pain and may appear and disappear. Eating or taking antacid medications can relieve this pain.

If you have this type of pain or severe pain that does not seem to go away, you should visit your doctor.

Several other symptoms may be associated with H. pylori infection, including:

  • Excessive belching
  • Feeling bloated
  • Nausea.
  • Acidity.
  • Fever.
  • Lack of appetite or anorexia.
  • Unexplained weight loss

Consult your doctor immediately if you experience:

  • Difficulty swallowing
  • Anemia.
  • Blood in the stool.

However, these are common symptoms that other conditions could cause. Healthy people also experience some signs of infection.

If any of these symptoms persist or if you are worried about them, it is always best to consult your doctor. Consult your doctor if you notice blood or black color in the stool or vomit.

Your doctor can perform many other tests and procedures to help confirm your diagnosis:

Physical exam:

During a physical examination, your doctor will examine your stomach to check for swelling, tenderness, or pain. They will also hear any sound inside the abdomen.

Blood test:

You may need blood samples, which will be used to look for antibodies against H. pylori. For a blood test, a health care provider will draw a small amount of blood from your arm or hand.

The blood will then be sent to a laboratory for analysis. This is only useful if you have never been treated for H. pylori before.

Stool test:

A stool sample may be needed to detect signs of H. pylori in the stool. Your doctor will give you a container to take home to catch and store a piece of your seat.

Once you return the container to your health care provider, they will send the sample to a laboratory for analysis.

This and breath tests will usually require you to stop medications such as antibiotics and proton pump inhibitors (PPIs) before the test.

Breathing test:

If you take a breath test, swallow a preparation that contains urea. If H. pylori bacteria are present, they will release an enzyme that breaks down this combination and releases carbon dioxide, which a particular device will detect.


If endoscopy is done, your doctor will insert a long, thin instrument called an endoscope into your mouth and your stomach and duodenum. An attached camera will send images back on a monitor for your doctor to see.

Any abnormal area will be inspected. If necessary, the special tools used with the endoscope will allow your doctor to sample these areas.

What are the complications of H. pylori infections?

H. pylori infections can lead to peptic ulcers, but the disease or ulcer can cause more severe complications. These include:

  • Internal bleeding can occur when a peptic ulcer breaks through the blood vessels and is associated with iron deficiency anemia.
  • Obstruction can happen when something like a tumor prevents food from leaving your stomach.
  • Perforation: that can happen when an ulcer breaks through the wall of your stomach.
  • Peritonitis: This is an infection of the peritoneum of the abdominal cavity lining.

Studies show that infected people also have an increased risk of stomach cancer. However, infection is a major cause of stomach cancer, most people infected with H. pylori never develop stomach cancer.

How are H. pylori infections treated?

If you have an H. pylori infection that is not causing any problems and you do not have an increased risk of stomach cancer, the treatment may not benefit you.

If you develop diseases associated with H. pylori infection, your prognosis will depend on the condition, how quickly it is diagnosed, and how it is treated. You may need to take more than one round of treatment to kill H. pylori bacteria.

If the infection is still present after a round of treatment, a peptic ulcer may return or, more rarely, stomach cancer may develop. If you have a family history of stomach cancer, you should have a test and treatment for H. pylori infection.