What is Small Bowel Bleeding?
Gastrointestinal bleeding is the top reason for hospital stays related to stomach issues. Usually, in these cases, around half the bleeds come from the upper part of the gastrointestinal tract, 40% from the lower part, and between 5% and 10% from lesions in the small bowel – the section of the digestive tract between two parts called the ligament of Treitz and the ileocecal valve.
We describe small bowel bleeding in two ways: obvious or hidden. Obvious bleeding involves clear blood loss, either through dark, tarry stools or bright red blood. Hidden bleeding isn’t outwardly visible but can lead to symptoms of anemia like tiredness, shortness of breath, or heart palpitations.
Identifying and diagnosing a small bowel bleed can be challenging for stomach specialists because the small bowel is long and hard to get to which makes it difficult to assess. The real issue is that most causes of small bowel bleeding are often missed due to these difficulties.
What Causes Small Bowel Bleeding?
The reason for bleeding in the small intestine can vary a lot, and often depends on a person’s age. For those under 40, it could be due to things like a specific type of blood vessel lesion, tumors, a pouch in the lining of the intestine called Meckel diverticulum, or inflammatory bowel disease. For those over 40, it’s often due to malformed blood vessels, the same type of blood vessel lesion, or ulcers caused by certain anti-inflammatory drugs.
The most common reason for gastrointestinal bleeding in the small intestine is an issue with the blood vessels, making up 30-40% of cases. The most common type of these is called angiodysplasia. These problems with the blood vessels can also be sparked by certain anti-inflammatory drugs. Other reasons can include tumors, a connection between the aorta and the intestine that shouldn’t be there (aorto-enteric fistula), certain medications, ulcers in the small intestine, and general inflammation of the small intestine.
Risk Factors and Frequency for Small Bowel Bleeding
Small bowel lesions are medical conditions that tend to affect around 5 to 10% of people experiencing gastrointestinal (GI) bleeding. Research has shown different common causes depending on the geographic location. In Asian countries, growths called neoplasms are the usual cause. However, in Western countries, angiectasias, which are clusters of dilated blood vessels, are the primary cause.
The specific type of lesion causing the bleeding often depends on the age of the patient. For example:
- Crohn’s disease and Meckel diverticulum are more commonly seen in younger people, under 40 years old.
- On the other hand, angiectasia and vascular lesions are more prevalent in people aged 40 and above.
- Neoplasms and Dieulafoy lesions, a rare but potentially serious gastric condition, are found equally in both younger and older age groups.
The prevalence of small bowel lesions does not differ between males and females. However, there isn’t enough data to understand the prevalence of these conditions amongst different ethnic groups.
Signs and Symptoms of Small Bowel Bleeding
When a patient comes in with signs of bleeding from the small intestine, it’s important for the doctor to get a comprehensive account of their medical history and conduct a thorough physical examination. This kind of bleeding can appear in different ways. It could be visible or could be hidden, only apparent in laboratory tests. It could cause severe symptoms similar to shock, or it could lead to slow, long-term bleeding which results in anemia. Having a thorough understanding of the patient’s history can point doctors towards the right diagnosis. This includes asking about:
- Past medical conditions, like heart valve disease, liver cirrhosis, chronic pancreatitis, or radiation therapy
- Previous surgeries, such as liver transplants, aortic aneurysm repairs, or bowel resections
- Medicines taken, especially those that can affect bleeding, like NSAIDs, blood thinners, or antiplatelet drugs
- Family health history, specifically any hereditary diseases like HHT or Peutz Jegher syndrome
- Lifestyle factors, like how much alcohol the patient drinks
The physical check-up can also provide clues for the diagnosis. Certain signs, like visible blood vessels on the skin (telangiectasia), spider-like blood vessels (spider angiomas), or enlarged veins around the belly button (caput medusa), or darkened lips in the case of Peutz-Jegher syndrome, may be identified. Moreover, a history of chronic pancreatitis might relate to rare causes, like bleeding from a pancreatic duct. For people living in tropical regions, doctors should also check if there’s a history of worms in the stool because this could be another possible cause of bleeding.
Testing for Small Bowel Bleeding
Small intestinal bleeding doesn’t occur very often, and it can be hard to diagnose because it takes a lot of time and expense. To start the diagnosis, doctors use a process called endoscopy. Advances in technology have opened up new ways to diagnose and treat this condition. Some of the latest methods, like capsule endoscopy and deep enteroscopy, now allow doctors to see further into the small intestine and address any problems they find. For now, there isn’t one diagnostic test that has both high sensitivity and specificity.
Endoscopy is usually the first step. With an ordinary endoscope, doctors can see the esophagus, stomach, and duodenum or the first part of the small bowel. If there are any abnormalities, the doctors can take immediate action.
Another way to find the source of the bleeding is by using a CT enterography, which lets doctors see the small bowel lining in detail. This test uses an oral contrast solution and is especially useful when the bleeding is happening somewhere that the endoscope can’t reach. However, it can’t be used for intervention. CT angiography, on the other hand, can help locate the active bleeding site and stop the bleeding. But, it can only be used if the bleeding rate is 0.3 to 0.5 mL/min. Nuclear tests with tagged RBC scans can find bleeding at a lower rate of 0.1 mL/min, making them more sensitive than CT angiography.
If the endoscopy doesn’t reveal the source of the bleeding, doctors may use capsule endoscopy. A tiny camera in a pill-like device takes pictures of the entire GI tract, giving doctors a detailed view. However, it can’t take biopsies or perform any treatments. There may be a rare risk of the capsule getting stuck in the GI tract in patients with previous abdominal surgeries.
When the lesion is deeper in the small bowel and can’t be seen by a standard endoscope, devices like the ‘push enteroscopy’ or ‘double-balloon enteroscopy’ can be used. These tools can push further into the small bowel to examine it in detail. They can treat affected areas, perform biopsies, and mark the area. It was found that these tools were able to identify the bleeding source in about 74% of patients and treated about 60% to 70% of them.
In cases when diagnosis isn’t possible using these methods, surgery may be the last resort. Intraoperative enteroscopy is performed under general anesthesia by surgeons and gastrointestinal specialists. They use a scope to examine the small bowel through an incision. This approach can manage the cause of bleeding, such as abnormal blood vessels, or remove masses or polyps. It has been found to effectively treat about 70% of patients.
Treatment Options for Small Bowel Bleeding
For small bowel bleeding, there are different treatment options available: conservative care, medication, use of imaging technology, endoscopy, and surgery. The choice of treatment depends on the specific circumstances, what resources are available, and the expertise of the medical team.
If the bleeding is hidden or difficult to detect (occult bleeding), it can often be managed outside of the hospital. The process usually involves using special imaging studies or endoscopy to locate the source of the bleeding and then treating it in the best way possible. Visible bleeding (overt bleeding) is generally considered a medical emergency and requires a stay in the hospital. Quick fluid replacement is vital, as well as locating where the bleeding is coming from using techniques such as angiography or scintigraphy. After figuring out where the bleeding is from, an enteroscopy (exam of the small intestine with a flexible, lighted tube) can be done to start the right treatment.
Drug therapies are a path to take when the bleeding areas are extensive and cannot be treated with more hands-on approaches. Drugs like estrogen, progesterone, and octreotide may be used. Octreotide has been found effective in different studies. These drug treatments work in several ways, including reducing blood flow to the abdominal organs, helping platelets (tiny blood cells that help your body form clots to stop bleeding) to cluster and form a clot, and slowing the growth of new blood vessels. Thalidomide, a drug that prevents the growth of blood vessels, can been used for consistent and returning blood loss as a result of faulty blood vessels. Some studies have shown that patients taking this drug required fewer blood transfusions.
There are also techniques involving endoscopy and imaging technology that can be used to treat blood vessel problems. The choice of technique will depend on what is available and the level of expertise of the treating team. These options could include electrocoagulation (using electricity to treat tissue), laser photocoagulation (using laser energy to stop bleeding), argon plasma coagulation, injection therapy, placement of hemoclips (small metal clips to control bleeding), endoscopic band ligation, or a combination of these methods. For ectopic varices (abnormal veins), endoscopic hemostasis (stoppage of bleeding) methods are used. Radiological techniques, like embolization (blockage of blood vessels), may be applied if endoscopic treatment is unsuccessful.
Surgery is considered the last option and is reserved for patients with recurrent bleeding who have not successfully been treated through endoscopy.
What else can Small Bowel Bleeding be?
- Inflammatory bowel disease (a long-term swelling of the intestine)
- Meckel’s diverticulum (a pouch-like bulge in the small intestine)
- GI stromal cell tumor (a rare tumor that starts in the gastrointestinal tract)
- Polypoid lesions (abnormal growths in the tissue surface, usually in the colon)
- Dieulafoy lesions (rare but serious condition that causes stomach bleeding)
- Angioectasia (a small dilation or swelling of a blood vessel)
- NSAID ulcers (stomach ulcers caused by non-steroidal anti-inflammatory drugs)
- Haemobilia (a rare disease where bleeding into the bile ducts occurs)
- Haemosuccus pancreaticus (a very rare condition where bleeding occurs from the pancreas into the digestive tract)
- Aorto-enteric fistula (a serious condition where there is abnormal communication between the aorta and intestine)
What to expect with Small Bowel Bleeding
There isn’t a lot of research about what happens after a small bowel bleed. However, what we do know is that the chances of dying in the hospital from it are low, less than 5%. Most of the hardship happens to patients that have other health issues. Sometimes, death can occur due to these other health problems getting worse, not specifically from the bowel bleed. Older age can increase the chances of death.
Interestingly, the death rate was higher in men than in women. Certain factors can make the situation worse. These include having a low blood volume, needing a blood transfusion, and having any conditions that affect the blood clotting process. Unfortunately, there aren’t many studies looking at small bowel bleeding affecting patients in the long run.
Possible Complications When Diagnosed with Small Bowel Bleeding
- Heart failure
- Difficulty in breathing
- Heart attack
- Infection
- Shock
- Death
Preventing Small Bowel Bleeding
Patients should be informed about possible signs of a gastrointestinal (GI) bleed. GI bleed can show itself in various ways, including dark stool (known as melena), and symptoms of anemia like tiredness, rapid heartbeat, and shortness of breath. Patients should be advised to avoid overusing pain relievers like nonsteroidal anti-inflammatory drugs, and to stop smoking and drinking alcohol.
If patients notice any change in their bathroom habits or if they notice any clear or hidden signs of a GI bleed, they should get in touch with their doctor. Patients also need to understand important warning signs such as low blood pressure or confusion. If these occur, it’s vital to get medical help immediately as these conditions require urgent care.
