Do you also suffer from frequent bowel movements, that is, diarrhea? Do you also suffer from diarrhea that is difficult to stop, sometimes watery, several times a day? Then this is something that may be important to you. Today, we will talk about a condition called Bile Acid Malabsorption (BAM) . Although the name may sound a bit complicated, let's explain it simply.
What is Bile Acid Malabsorption?
Simply put, this is a disease of our digestive system . In particular, it can be a major cause of chronic diarrhea , that is, continuous diarrhea. When bile acids in our intestines are not properly absorbed by the body, they accumulate in the intestines. Then the chemical balance inside is disturbed. Due to this excess bile acids, our colon is sent a message to secrete more water. That is why watery diarrhea occurs. Think of it like water going down a pipe, but this is what happens when that water goes out of control.
What are bile acids?
Now you may be wondering, "What are these bile acids?" Bile is a substance produced by our liver . When the liver cleans our blood, it separates out waste products like toxins, dead blood cells, and excess cholesterol and forms bile. The different types of acids in this bile combine to form bile acids . These acids help keep the lipids in the bile liquid.
This bile from the liver is sent through the bile ducts to our small intestine to help digest food. In the small intestine, these bile acids help the body digest the fats in the food we eat and absorb them. When that job is done, these bile acids are reabsorbed into our body, travel through the bloodstream to the liver, and are used again to make bile. This is like a recycling process.
What is "Malabsorption"?
"Malabsorption" simply means that our intestines are unable to properly absorb chemicals that we need to absorb. This can be due to a problem with the intestines themselves, or it can be due to a chemical imbalance. For example, when there is too much or too little of a certain chemical, the intestines may not be able to properly absorb it.
Who is most affected by this situation?
In the past, bile acid malabsorption (BAM) was not well-diagnosed, so it went undiagnosed in many people. However, recent research suggests that at least 30% of people with functional diarrhea disorders may have BAM. Functional disorders are conditions that have no clear cause and are not easily detected by a medical test. For example , Irritable Bowel Syndrome (IBS) .
BAM can be seen in people with the following medical conditions:
- Microscopic colitis
- Crohn's disease
- HIV-related enteritis
- Persistent diarrhea after a bacterial infection
- Exocrine pancreatic insufficiency
Also, this condition can occur in people receiving certain medical treatments:
- Surgical removal or alteration of the ileum, the last part of the small intestine.
- Gallbladder removal surgery (cholecystectomy) .
- Radiation therapy , especially to the abdomen and pelvis.
- Chemotherapy .
- Use of Metformin, a drug used for type 2 diabetes.
What are the symptoms of this?
The symptoms that are commonly seen are:
- Watery diarrhea
- Frequent need to go to the bathroom
- Painful cramps in the stomach
- Sudden urge to go to the bathroom and difficulty holding in stool
Some people may also have the following symptoms:
- Abdominal bloating
- Gas and the pain it causes
- Fatty stools (Steatorrhea)
- Indigestion
Long-term effects may include:
- Dehydration
- Extreme fatigue despite adequate rest
- Headache
- Dizziness
- Nausea
- Some people gain weight, others lose weight.
Most of the time, about half of those who suffer from these symptoms have them all the time . The other half only experience symptoms occasionally .
Why does bile acid diarrhea occur?
The main symptom of bile acid malabsorption is bile acid diarrhea (BAD) . This is caused by bile acids accumulating in our large intestine (colon) , where food waste is converted into stool. Normally, 95% of the bile acids in our small intestine are reabsorbed in the last part of the small intestine, the ileum, before they reach the large intestine.
However, if excess bile acids are not absorbed in this way, they pass along with other waste products into the large intestine. In the large intestine, these bile acids irritate the lining of the intestine. This causes it to secrete more fluid, and the muscles that push the stool forward become more active. This is why diarrhea occurs frequently and suddenly, and stomach cramps occur.
What are the causes of decreased bile acid absorption?
Now the question is, why do these bile acids accumulate in the intestines? Researchers have divided BAM into four possible causes. Sometimes these are also classified as primary and secondary .
- Primary BAM: This is caused by our liver producing too many bile acids (types 2 and 4).
- Secondary BAM: This occurs when our small intestine is damaged due to a disease, surgery, or radiation therapy (types 1 and 3).
Type 1 BAM: This is caused by a problem in the ileum, the last part of the small intestine. This is called true malabsorption because the problem begins in the absorption stage of the bile acid cycle. You may also have Type 1 BAM if you have had the last part of the small intestine surgically removed, altered, or bypassed as part of another medical condition. The ileum can also be damaged by conditions such as Crohn's disease and radiation therapy. If there is significant damage, absorption is impaired.
Type 2 BAM: This is sometimes called "idiopathic." This means it happens suddenly, without a cause. However, current research suggests that it is caused by a problem with the chemical signaling system between our intestines and liver. This signaling system normally controls the enterohepatic circulation. These signals tell the liver when to make and send more bile acids, and when to stop, reabsorb, and recycle them. But in Type 2 BAM, the message to "stop" doesn't get through properly. So, the liver keeps sending bile acids—more than the ileum can absorb.
Type 3 BAM: This is caused by diseases that affect the ileum along with other parts of our digestive system. For example, conditions like celiac disease , chronic pancreatitis , and Small Intestinal Bacterial Overgrowth (SIBO) .
Type 4 BAM: This occurs as a side effect of taking the diabetes drug metformin , which causes excess bile acid production.
What are the long-term effects of this condition?
If you have severe bile acid malabsorption, you may develop a bile acid deficiency over time. This means that when too much bile acid is excreted in the stool and not recycled back to the liver, the liver doesn't have enough bile acids to make bile. If there is less bile in the small intestine, it can affect your digestion and nutrition.
A lack of bile acids in the small intestine reduces the absorption of fats and fat-soluble vitamins (A, D, E, and K). This can lead to malnutrition and specific problems associated with fat-soluble vitamin deficiencies. For example, vitamin D deficiency affects bones, and vitamin A deficiency affects vision.
People with Type 1 BAM, in particular, may also develop vitamin B12 deficiency . This is because vitamin B12 is absorbed through the ileum. In this case, the deficiency is not caused by BAM itself, but by the condition that causes Type 1 BAM - that is, the dysfunction of the ileum. Symptoms such as nausea, dizziness, and fatigue may accompany this.
If you have a bile acid deficiency, which reduces fat absorption and prevents you from burning enough calories, you may lose weight. However, in some cases, poor bile acid absorption can lead to weight gain. This seems to be related to metabolism. BAM, or the conditions that cause it, can affect how your body uses calories and stores them as fat.
How is this disease diagnosed?
Current medical guidelines recommend that anyone with persistent diarrhea without a clear cause should be tested for bile acid malabsorption. But these tests are not available everywhere. Some doctors will check for this and prescribe medications called bile acid sequestrants to see if they provide relief.
There are several tests that can be used to diagnose bile acid malabsorption:
- SeHCAT test: This is considered the best test to diagnose BAM, but many countries, including Sri Lanka, do not have the facilities to do this. This is a nuclear medicine imaging test . That is, a low-dose radioactive substance is injected into the body, and a computer monitors how it moves through the body and takes pictures. In this test, you swallow a capsule containing a synthetic bile acid called SeHCAT along with this radioactive substance. This capsule goes to the small intestine and is absorbed as quickly as possible by the bile acids in your body. A gamma camera measures the level of SeHCAT in your body on the first day and after seven days. If less than 85% of SeHCAT remains after seven days, it can be diagnosed as having BAM.
- Serum C4 test: This is a blood test. It is considered the next best option after the SeHCAT test. It measures the level of an enzyme called C4 in the blood. C4 levels are related to how much bile acids your liver produces. A high C4 level is a good indicator that you have primary BAM (types 2 and 4). People with secondary BAM (types 1 and 3) can also have high C4 levels if the liver starts producing more bile acids to compensate for the reduced absorption. This test is therefore useful for many people. However, it can also give false results in people with certain conditions, such as high cholesterol and metabolic non-alcoholic fatty liver disease .
- Fecal Bile Acid Test (Fecal BA test): This measures the amount of bile acids in your stool. This is the most direct way to measure bile acid malabsorption. However, it is technically a bit more complicated and can only be done at select health centers. This test requires special preparation. You will need to follow a special diet for a few days beforehand, and then collect stool samples for 48 hours. Specialists will test your stool for bile acids in a lab. If your bile acid levels are high, it means that too much bile acid is being absorbed in the small intestine and is being passed into the large intestine, causing bile acid diarrhea.
What are the best treatments?
The first-line treatment for bile acid malabsorption is a class of drugs called bile acid sequestrants or bile acid binders . Cholestyramine and colestipol are the most commonly prescribed. Colesevelam is an unlicensed option, but some people find it easier to use.
These bile acid sequestrants are positively charged particles that bind to negatively charged bile acids in the intestines, preventing them from being broken down into smaller pieces that can be absorbed. This binding also prevents the bile acids from acting on the large intestine and causing diarrhea. This helps reduce the symptoms of BAM.
Are there any side effects of the treatment?
These medications usually come in powder form. They need to be mixed with a liquid and taken. Some people find the taste and texture difficult to swallow. Others experience BAM symptoms as well as unpleasant side effects. These include constipation , nausea, bloating, and gas.
Also, bile acid sequestrants can bind to fat-soluble vitamins in the small intestine. This can prevent the small intestine from absorbing them. Some people who take bile acid sequestrants may need to take vitamin supplements. They may also need to be taken in a way that bypasses the digestive system, such as by injection .
Can this condition be completely cured?
Whether bile acid malabsorption can be cured depends on the cause. Some causes can be cured, while others cannot. If the underlying cause is treated directly, sometimes the BAM condition can improve. In other cases, even if the cause cannot be cured, there is a good chance that the symptoms can be successfully treated.
Important: Don't panic! BAM can be managed. The most important thing is to follow your doctor's instructions.
What makes symptoms worse?
The bile acid cycle is triggered by the amount of fat in your diet. If there is too much fat in the small intestine, the liver gets a chemical signal telling it to "send more bile." More bile means more bile acids are going into the large intestine. That's why doctors recommend a low-fat diet to help manage BAM.
When should you see a doctor?
If you have persistent diarrhea for no apparent reason, ask your doctor about bile acid malabsorption. This is a poorly understood and under-diagnosed condition, so not all doctors will immediately think about it. So ask your doctor to test you for it, or refer you to a specialist who knows about it.
Many people spend years trying to find a proper diagnosis and effective treatment for their unexplained diarrhea. For those with bile acid malabsorption, there is hope that those days will come to an end. With greater awareness of the condition and easier detection methods, diagnosis will improve.
Although there are many causes of bile acid malabsorption, the treatment is the same in all cases. A doctor who suspects BAM may prescribe treatment, perhaps as a way to confirm it. Many people with BAM can successfully manage their symptoms with bile acid sequestrants and dietary changes.
The most important things to remember (Take-Home Message)
Okay, so let's summarize what we talked about today:
- Bile acid malabsorption (BAM) is a condition that can be a major cause of chronic diarrhea.
- This happens because bile acids are not properly absorbed by the intestines, but accumulate in the large intestine, causing watery diarrhea.
- Various medical conditions, surgeries, and some medications can cause this.
- Symptoms may include frequent diarrhea, stomach pain, and bloating.
- The disease can be diagnosed through tests such as the SeHCAT test, serum C4 test, and fecal bile acid test .
- The main treatments are medications called bile acid sequestrants and a low-fat diet .
- Depending on the cause, it may or may not be completely curable, but the symptoms can be well controlled.
- If you have persistent, unexplained diarrhea, be sure to seek medical advice and ask about BAM.
Don't worry, if you understand this condition and treat it properly, you too can find relief. Be healthy!
` Bile acids, diarrhea, intestines, absorption, liver, symptoms, treatment
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