UNDERSTANDING SHORT BOWEL SYNDROME (SBS): CAUSES, SYMPTOMS, AND TREATMENT
Medically Reviewed by Dr. Sony Sherpa (MBBS)
Short Bowel Syndrome (SBS) is a complex condition affecting the body's nutrient absorption capacity. It occurs after surgical removal of a significant portion (over two-thirds) of the small intestine[1]. Intestinal resection becomes necessary to treat congenital abnormalities or digestive conditions, such as Crohn's disease or severe injuries.
The reduced length of the small intestine results in malabsorption and malnutrition, significantly impacting physical and mental health. Timely detection and intervention are vital to preventing complications for those having undergone intestinal resection who are at the highest risk.
This article discusses SBS, elucidating its causes, symptoms, diagnosis, and various treatment options, including nutritional support, medications, and surgical interventions.
What is Short Bowel Syndrome?
Short bowel syndrome is a medical condition that arises due to intestinal resection or removal of a large part of the small intestine.[2]
The small intestine comprises a lengthy portion of the digestive system, measuring approximately 275 to 850 centimeters in adults. Roughly nine liters of fluids pass through the small intestine daily, seven of which are slowly absorbed by the small intestine and two by the large intestine over the course of the day.[3] A large portion of all the nutrients we consume are taken up in the process, including water, electrolytes, fats, and vitamins.
The first 100cm of the digestive tract absorbs most nutrients. However, depending on which section of the tract is missing, the gut may fail to absorb specific nutrients, leading to deficiencies.
Patients with SBS are missing one to two-thirds of their small intestine, retaining 180 to 200 cm. This significant reduction in length radically compromises digestion, lending itself to severe malnourishment. Water and sodium absorption are affected in every case of SBS as these two nutrients are absorbed in every portion of the small intestine, dramatically raising the risk for dehydration in those affected.
Most SBS cases are acquired, occurring after surgery to remove a part of the small intestine due to diseases or injuries. However, it can also be a congenital condition, meaning some individuals are born with an unusually short small intestine.
Causes of Short Bowel Syndrome
The surgical resection or removal of a sizable portion of the small intestine is the primary cause of short bowel syndrome. This surgery, known as bowel resection, is often necessary due to conditions that damage the intestines.
The severity of SBS is directly proportional to the amount of intestinal resection. In other words, the shorter the intestine, the more serious the condition.
Causes of SBS can be congenital or acquired.
Congenital Causes
- Intestinal Atresia: A birth defect where portions of the small intestine fail to develop properly, leading to obstruction or absence of intestinal segments.
- Meconium Ileus: A blockage in the intestine often associated with cystic fibrosis.
- Malrotation: An abnormal rotation of the intestines during fetal development that can lead to twisting (volvulus) or obstruction.
- Gastroschisis and Omphalocele: Birth defects involving the protrusion of the intestines through an opening in the abdominal wall.
Acquired Causes
- Crohn’s Disease: A chronic inflammatory condition of the gastrointestinal tract that can lead to severe damage and sections of the intestines being removed.
- Radiation Enteritis: Inflammation of the intestines caused by radiation therapy, potentially resulting in tissue damage that requires surgical removal.
- Mesenteric Ischemia: A condition where the blood supply to the intestines is compromised, leading to tissue death and the need for resection.
- Volvulus: Twisting of the intestine that can cause blockage, cutting off blood supply and necessitating surgical intervention. Volvulus can develop due to tumors, Meckel diverticula, pregnancy, or high-fiber diets, to name a few[4].
- Necrotizing Enterocolitis (NEC): A severe gastrointestinal condition primarily affecting premature infants, where sections of the intestines become necrotic.
- Tumors: Malignant or benign growths in the small intestine that may require removal of the affected portion.
- Abdominal Trauma: Physical injuries that damage the intestines and may necessitate partial removal.
Up to 75% of cases were found to have undergone one mass resection of the tract, while 25% occurred due to multiple resections over time.
Symptoms and Complications of Short Bowel Syndrome
Short bowel syndrome can lead to a range of symptoms, primarily due to the reduced ability of the small intestine to absorb nutrients. The most prevalent symptom is diarrhea, which can lead to dehydration if not managed properly.
The symptoms and complications of SBS vary depending on age and the extent of the resection:[5]
Infants and Young Children
- Severe diarrhea
- Failure to thrive
- Dehydration
- Electrolyte imbalances
- Poor nutrient absorption, leading to delayed growth and development
Adolescents
- Chronic abdominal pain
- Nutrient deficiencies
- Difficulties with weight gain
- Deficiencies in vitamins and minerals impacting bone health and overall energy levels
Adults
- Chronic diarrhea
- Malnutrition
- Fatigue
- Increased risk of intestinal failure-associated liver disease
- Kidney stones
- Bile salt diarrhea
- Bowel obstruction
Older Adults
- Muscle wasting
- Cognitive impairments due to nutrient deficiencies
- Potential heart conditions
Malnutrition[6] and malabsorption[7] can induce the following symptoms as well:
- Loose, greasy, foul-smelling stools
- Swelling (distention) of the abdomen
- Swelling of the tissues of the legs and feet (peripheral edema)[8]
- Hair loss
- Brittle nails
- Pale skin
- Low blood pressure
- Dizziness
- Breathing difficulties
- Heart arrhythmia
- Muscle wasting
- Inability to focus
- Low mood
- Tingling sensations or numbness in the periphery
- Joint and muscle stiffness and pain
The complications of SBS can be severe and may include[9]:
- Kidney failure
- Kidney stones
- Anemia
- Osteoporosis
- Chronic infections
- Stunted or delayed growth in children
These complications arise from the body's struggle to process and absorb nutrients effectively.
Symptoms and their severity may vary significantly from person to person. Regular monitoring and medical check-ups are crucial for managing these symptoms and preventing complications.
Diagnosis of Short Bowel Syndrome
Diagnosing short bowel syndrome requires an assessment of the patient’s medical history, a physical examination, and confirmatory diagnostic tests. The process begins with a detailed discussion about the patient's symptoms, dietary habits, and any previous surgeries involving the small intestine.[10]
The physical examination often includes checking for signs of malnutrition and dehydration. This can involve assessing the patient's weight, skin elasticity, and overall appearance. The doctor may also check for abdominal tenderness or swelling.
Diagnostic tests often include:
- Blood tests can assess nutritional status and check for anemia in SBS patients.
- Stool tests can identify fat malabsorption, a common problem in SBS.
- Imaging studies, such as CT scans or MRIs, can provide a detailed view of the small intestine. These images can help doctors assess the length and condition of the remaining bowel.
- Colonoscopy to examine the colon.
- Endoscopy to examine the upper portion of the tract.
Early diagnosis is crucial in managing SBS effectively and preventing complications.
Management and Treatment for Short Bowel Syndrome
Management of short bowel syndrome is a complex process. It involves a multidisciplinary approach, with a focus on nutritional support, medications, and possibly surgery.[11]
The goal is to maximize remaining bowel function and improve the patient's quality of life.
Nutritional Support and Dietary Management
Nutritional support is a cornerstone of SBS management. It aims to ensure the patient receives adequate nutrients and hydration. This can involve dietary modifications, oral rehydration solutions, and in some cases, parenteral nutrition.
Helpful dietary changes include eating small, frequent meals and including specific nutrients in the diet[12]. For instance, a high-calorie diet of complex carbohydrates and proteins is generally well-absorbed. On the other hand, foods to avoid with short bowel syndrome include fats and FODMAPs, as they can be harder to digest and may need to be limited.[13]
In addition to dietary changes, nutritional therapies such as enteral nutrition (EN) and total parenteral nutrition (TPN) may be necessary.
- Enteral nutrition (EN) involves feeding directly into the stomach or small intestine through a tube.
- Total parenteral nutrition (TPN) provides nutrients through a vein, bypassing the digestive system entirely.
In some cases, the patient can lower their reliance on TPN after intestinal adaptation occurs and the body acclimatizes to having a shorter intestinal tract.
Dietary management for SBS is highly individualized. What works for one patient may not work for another. Therefore, working closely with a dietitian is crucial in managing SBS effectively.
Medications and Emerging Treatments
Medications are an important part of SBS management. They can help manage symptoms, enhance nutrient absorption, reduce complications, and promote intestinal adaptation. The final prescription will depend on the patient's specific needs and symptoms.
Some common prescriptions for SBS include:
- Anti-diarrheal medications can help manage common symptoms of short bowel syndrome.
- Proton pump inhibitors and antihistamines can reduce stomach acid production and improve nutrient absorption in individuals with SBS.
- Bile acid sequestrants may help to ease fat-related diarrhea.
Emerging treatments are also showing promise in SBS management. These include medications that stimulate intestinal adaptation and reduce the need for parenteral nutrition. However, more research is needed to understand their long-term effects and benefits fully.
Surgical Advances and Intestinal Transplant
In some cases, surgery may be necessary. This can involve procedures to improve the function of the remaining bowel or, in severe cases, an intestinal transplant. Surgical procedures can help improve the function of the remaining bowel and reduce complications.
These procedures can include bowel lengthening, tapering, and resection. Examples of lengthening techniques include[14]:
- STEP Procedure (Serial Transverse Enteroplasty): The intestine is cut in a zigzag pattern and reconnected, widening and lengthening it.
- LILT Procedure (Longitudinal Intestinal Lengthening and Tailoring): The intestine is split lengthwise and reconnected, increasing its diameter.
The benefits and risks of each surgery vary, and selection is based on the individual needs and conditions of the patient.
In extreme cases, an intestinal transplant may be considered.
This involves replacing the diseased small intestine with a healthy one from a donor. While this can significantly improve quality of life, surgery also maintains significant risks and challenges. It is a last resort when all other treatments have failed.
The Role of Ostomy
Ostomies often play a critical role in the management of short bowel syndrome, either as a temporary measure to divert waste during intestinal healing or as part of long-term management. For some patients, an ostomy may be a precursor to advanced interventions such as intestinal lengthening procedures or transplantation.
Ostomy Care in Daily Life
Many patients with SBS may require an ostomy, a surgically created opening in the abdominal wall for waste elimination. Ostomy care involves managing the stoma and the associated appliance to prevent skin irritation, maintain hygiene, and ensure a secure fit.
Regular follow-ups with ostomy care specialists can help address concerns such as leaks, discomfort, or infections. Additionally, individuals may benefit from dietary adjustments to reduce output or manage dehydration, which is a common challenge in patients with an ostomy.[15]
Living with Short Bowel Syndrome
Living with SBS can be challenging. It often requires significant lifestyle adjustments and ongoing medical care. However, individuals with SBS can lead fulfilling lives with the right support and management.
One of the key aspects of living with SBS is dietary management. This involves learning what foods are well-tolerated and which ones to avoid. It may also involve adjusting meal sizes and frequencies to optimize nutrient absorption.
Regular medical care is also crucial. This includes regular check-ups, monitoring for complications, and adjusting treatment plans as needed. Maintaining a close patient relationship with your healthcare team and communicating any changes or concerns is essential.
Physical activity and mental health support are also important. For those living with SBS, regular exercise can improve general health and wellbeing. Patients experiencing the emotional difficulties of living with SBS may benefit from mental health support, such as counseling or support groups.
Support networks (family, friends, healthcare professionals, support groups) are vital in managing SBS, offering emotional and practical support to navigate the challenges of living with the condition.
Working closely with a healthcare team that can devise a comprehensive, personalized management plan is essential.
What is Intestinal Adaptation?
Intestinal adaptation is the natural physiological process where the remaining portion of the intestine undergoes structural and functional changes to maximize nutrient and fluid absorption after bowel resection. This adaptation typically begins shortly after surgery and can last for up to two years.
Key mechanisms include an increase in the surface area of the intestinal lining, elongation of villi, and enhanced digestive enzyme activity. Patients may receive nutritional support, such as parenteral nutrition or specialized diets, to aid this process. Therapies involving growth factors or hormones, including GLP-2 analogs, can also stimulate adaptation and improve long-term outcomes.
Latest Advancements in SBS Treatment
The field of SBS treatment is constantly evolving. Significant advancements have been made in recent years, particularly in medication and surgical techniques. These advancements aim to improve nutrient absorption, lower the risk of complications, and enhance life quality for individuals with SBS.
Emerging medications, such as GLP-2 analogs, are promising to enhance intestinal absorption and reduce the need for parenteral nutrition[16]. Meanwhile, advancements in surgical techniques are improving outcomes for patients who require bowel lengthening or transplantation.
Researchers are also exploring using stem cells to regenerate damaged intestinal tissue or potentially even grow new sections of the intestine. Bioengineered intestinal tissues that make use of stem cells and other biologics are under development, potentially providing partial to complete relief for those with SBS in the future.[17]
While these advancements are promising, ongoing research is crucial. Clinical trials and patient registries are vital to understanding SBS and developing more effective treatments.
Conclusion
Being a complicated condition, short bowel syndrome necessitates comprehensive care. With advancements in treatment and a multidisciplinary approach, individuals with SBS can lead fulfilling lives.
Continued research and patient education are crucial to improving outcomes. With the right support, individuals with SBS can navigate their journey with confidence and resilience.
To search for the best Gastroenterology Healthcre Providers in Azerbaijan, Germany, Hungary, India, Malaysia, Poland, Slovakia, Spain, Thailand, the UAE, the UK and The US please use the Mya Care Search engine.
To search for the best Dietitian/Nutritionists in Croatia, Germany, India, Malaysia, Slovakia, Spain, Thailand, Turkey, the UAE, the UK and The USA, please use the Mya Care search engine.
To search for the best doctors and healthcare providers worldwide, please use the Mya Care search engine.
Sources:
