Gallstones

The gallbladder is a pear-shaped organ located on the liver that stores bile.  It is connected to the intestinal system by the cystic duct which in turn empties into the common bile duct.  When we eat a large or fatty meal, nerve and chemical signals cause our gallbladder to contract thereby adding bile into our digestive system.

Gallstones or cholelithiasis are collections of sediment in the bile which form a solid structure not unlike a marble or stone. Most of them are soft and can be easily crushed into powder. They are collections of either cholesterol and or calcium-bilirubin. The vast majority (80%) are principally composed of cholesterol but only a small number (10%) are pure cholesterol. These stones are yellow or brown. Calcium bilirubinate stones are black and usually much harder than the cholesterol stones. They comprise about 20% of gallbladder stones. Gallstones vary in size from tiny grains like salt to large 1 to 2 inch diameter rocks.
 

Gallbladder disease:

• is more common in women than in men
• is a disease primarily of middle age
• is more common in overweight people
• usually occurs after childbirth or during pregnancy
• is more common in fair-skinned people

Despite these statements, it is not uncommon for a twenty-year-old, dark skinned, thin male or female to get gallstones.  However, based on these relationships and numerous studies, we known that there are various factors to gallstone formation including:

• Changes in sex hormones as might occur during pregnancy or with the birth control pill
• Genetic factors that give a familial predisposition
• Periods of rapid weight loss or weight gain
• Periods of/or repetitive fasting
• Obesity
• Diseases which either impair the absorption of bile from our intestinal tract, like Crohns disease, or that lead to rapid and abnormal breakdown of red blood cells, such a thalassemia or sickle cell anemia

Ultimately, gallstones result from an inability to keep cholesterol dissolved in water.  Just like fats in our intestinal system need bile salts and other substances in bile to be absorbed, cholesterol needs the same substances to keep it dissolved in water, the primary component of bile.  If there is too much cholesterol or not enough of the other substances, the cholesterol will form crystals.  Over time, these crystals grow into stones.

Typical symptoms of gallstones are of three types: 

• Pain between the breast bone and the belly button (epigastric) pain or discomfort
• Pain beneath the breastbone (substernal), which may seem like a heart attack
• Pain in the right upper quadrant, which may shoot to the right side of the back or up to the right shoulder

These pains, which are referred to as biliary colic, may be mild or severe, sharp or crampy, and may last from minutes to hours.  They typically occur a few hours after eating and most commonly at night or early morning.  They frequently wake the patient from sleep.  The pain may be associated with nausea and vomiting.  It is often associated with bloating.  In fact, bloating and fullness are common symptoms that may be related to gallstones and unassociated with pain. 

However, bloating and fullness may occur for other reasons.  If that is the case, treatment of the gallstones will not lead to relief of the symptoms.  In fact, the only reliable symptoms of gallbladder disease, which will almost always be eliminated by removing the gallbladder, are the three pain syndromes noted above.

Gallstone Q&A

Do the pain and symptoms occur in all patients with gallstones?

No.  There are over 20 million Americans with gallstones but only about 750,000 gallbladders removed per year.  In addition, about 1 million new cases will be diagnosed each year.  Therefore, most patients with gallstones have no symptoms or symptoms so mild they do not affect their lifestyle.  It is estimated that only 20% of people with gallstones and no symptoms will develop symptoms during the next twenty years of their life.  However, people who do have symptoms are likely to continue to have symptoms.  Furthermore, in a large percentage of symptomatic patients, the frequency and severity of the attacks increase over time.

Why do these symptoms occur?

After we eat there are chemical (hormonal) and nerve signals from our intestinal tract (duodenum) which cause the gallbladder to contract.  When there are no stones present, the gallbladder empties its bile freely.  However, when stones are present, the stones can block the exit of the gallbladder at the cystic duct.  This leads to secretion of water into the gallbladder to relieve the obstruction by increasing the force of contraction. However, because the exit is blocked, this leads to distention (swelling) of the gallbladder, which in turn causes the epigastric and or substernal pain.  

Continued distention of the gallbladder leads to reduced blood flow to the wall of the gallbladder and to inflammation.  This is associated with pain in the right side of the upper abdomen. The nausea, vomiting and bloating are a non-specific intestinal response (visceral response) to these insults.  

Usually after a period of time, the stone will fall out, bile will exit, the distention is relieved and the pain goes away.  However, if there was a lot of inflammation, some residual discomfort may remain for hours to days.  The length of time this residual pain is present is related to the severity of the attack.  Occasionally, the stone gets firmly stuck and does not fall back into the gallbladder.  This leads to continued inflammation and pain known as acute cholecystitis.  This situation is similar to acute appendicitis although the gallbladder is not as likely to rupture as the appendix is.  Typically, patients with acute cholecystitis have large gallstones.  They are much sicker than patients with biliary colic, frequently have a fever and need emergency or urgent surgery.

What are my chances of more symptoms?

The National Cooperative Gallstone Study was performed in the early 1980's to evaluate this question as well as other.  The results of these studies revealed that 70% of patients with previous symptoms had at least one more episode of pain during a two year period if the gallstones were not treated.  Furthermore, approximately 50% had severe attacks and 20% had more than one attack.  Therefore, you can expect attacks in the future if you have had them in the past.  The question is when they will occur.  Unfortunately, they often will occur when you least want them, Murphy's Law.

Is the size or number of the stones related to whether or not patients have symptoms?

No.  Patients may have one small stone and have severe and repetitive symptoms while others with multiple large stones may have none.  However, it is important to note that the type of symptoms and complications of gallstone disease are related to the size of the stones.  For example, patients with gallstones greater than one centimeter in size are more likely to get acute cholecystitis than those with gallstones less than one centimeter in size.  Patients with gallstones greater than 3 centimeters in diameter are more likely to get  gallbladder cancer than those with stones smaller than 3 centimeters or no stones. (Nonetheless, gallbladder cancer is so rare it is not a problem worth worrying about.)  Patients, on the other hand, with small, less than 1/2 centimeter stones are more likely to get passage of the stones through the cystic duct into the common duct.  This can lead to two severe and life threatening problems: pancreatitis and obstructive jaundice.

• Pancreatitis is a chemical inflammation of the pancreas, the organ that makes insulin and digestive enzymes that break up food in our intestinal tract.  It results from the passage of a stone down the common duct and out the end of the common duct into the intestine.  As the stone passes through, it can block the exit of the duct from the pancreas which also empties into the common duct or the intestine near the common duct.  Because the pancreatic duct contains digestive enzymes that breakdown food, the blockage can lead to digestion of the pancreas itself. As a result, patients with acute pancreatitis can develop severe complications and death.  Acute pancreatitis is usually associated with severe pain in the epigastrium that radiates straight back, is worse lying down and better sitting up.  It is associated with vomiting and retching.
• Obstructive jaundice from stones (choledocholithiasis) is the condition whereby stones enter and block the flow of bile in the common duct from the liver to the duodenum.  This results in a back up of bile which causes the liver to not work correctly, fats to be malabsorbed, the eyes and skin to turn yellow, the urine to turn tea colored and the stool to turn clay colored.  Because the bile becomes stagnant in the common bile duct, the risk of infection is great and can be life threatening.  It is usually associated with severe pain in the epigastrium.

Gallstones are diagnosed by various radiological studies.  

• The first and most common test is an ultrasound, which uses sound waves to determine if stones are present. This test has no pain associated with it and is not invasive. The technician places jelly on the patient's abdomen and slides a wand across it. The wand emits a sound wave which bounces back to the wand and ultimately to a computer, which produces a picture.
• Another test is an oral cholecystogram (OCG).  For this test the patient takes 8 pills the night before the x-ray is taken. The x-ray is taken the next day. The pills dissolve, are absorbed and then excreted into the bile to form a dye that outlines the gallbladder, giving an image which can be seen on the x-ray. The image may be normal or may show stones. If no image shows up, the patient either did not absorb the pills or the gallbladder does not work. In this case, the patient is asked to take the pills again and repeat the x-ray. If there is still no picture, the gallbladder is diseased.

These tests are usually done because you are having symptoms that are consistent with gallstones or your doctor is looking for another problem, such as an ovarian cyst.

In general, only those patients with symptoms should be treated.  Patients with no symptoms should be observed unless they fall into special categories:

• Patients less than 40 years of age are candidates for treatment because they have a long life ahead of them.
• Patients with diabetes (sugar) have a higher complication and death rate from gallbladder surgery during acute attacks and therefore should be treated once they are known to have stones.
• Like patients with diabetes,  patients with chronic diseases that will get worse but are currently stable and in general good health should be considered for elective treatment. The risk of emergency surgery or elective surgery in these patients is very high if their overall condition has deteriorated.
• Patients with diseases that increase the risk of gallstones, such as blood disorders, should be considered for elective treatment even if they have no symptoms because the risk of common duct stones is frequently higher.
• Finally, patients with a calcified gallbladder should have their gallbladders removed because of a very high association of this entity with gallbladder cancer (30-70%).

Although nausea, bloating, heartburn and nonspecific pain can be produced by gallstones, the best and most specific symptoms referable to gallstones are the three pain complexes noted above.  In a study performed in Italy where an entire town had an ultrasound and filled out a questionnaire, 90% of the patients with the pain complexes had stones on ultrasound but only 50% of those with non-specific symptoms had stones.  That is, those with non-specific symptoms, such as nausea, bloating or belching, were as likely to have stones as not and therefore as likely to benefit from treatment as not.

No. There is no known relationship between cholesterol in the blood and the formation of gallstones. However it is important to recognize that measures taken to lower cholesterol such as dieting and cholesterol lowering drugs can lead to gallstone formation.
 

Not directly. If your diet does not change after your gallbladder is removed, there will be no change in your blood cholesterol level. However, patients who have gallbladder symptoms may be unconsciously avoiding fats and cholesterol rich foods. After your gallbladder is removed you will no longer have symptoms, which may lead to a diet that is higher in fats and cholesterol. This may, in turn, lead to an elevated cholesterol level.

Bile is a complex fluid composed of bile salts, cholesterol and other molecules (phospholipids and lecithin).  The bile salts are the breakdown products of hemoglobin, the oxygen carrying pigment of red blood cells.  Bile salts and bile itself are formed in the liver and excreted into bile ducts which converge in the liver to form the main bile ducts.  Just as there is a left and right liver lobe, there is a left and a right hepatic (liver) bile duct which join to form a single bile duct, the common hepatic or common bile duct.  

The common bile duct enters the duodenum, the earliest part of the small intestine where digestion and absorption of food begins.  You may recognize the word duodenum since it is the most common site for ulcers.  Normally we make 1000 to 1500cc of bile a day. It is constantly produced.  As a result, there is always a steady amount of bile entering our intestinal tract.  Some of it goes into the gallbladder as it comes down the duct.  It is stored there until neurochemical signals cause the gallbladder to contract.  This provides additional bile to the intestinal system.  These neurochemical signals usually occur after eating.

Yes. We absolutely need bile to absorb fats.  Our intestinal lining can absorb water but not fats.  Since fat is not dissolvable in water (like oil in water) we can not absorb fats unless something makes the water and fats attach.  This is the function of bile; it can bind to both water and fat.  Therefore, when we absorb water, the fats absorb with it if bile is present to link the water to the fat.  If we do not have any bile we will not be able to absorb fats.  This will in turn lead to severe deficiencies of essential fats, alter our metabolism, cause significant problems which will impair living and lead to diarrhea.