Bowel Obstruction

What is Bowel Obstruction?

Bowel obstruction is a condition where the small or large intestines are blocked partially or completely. This blockage could be due to a physical problem (mechanical) or because the intestines aren’t functioning properly (functional). It often results in symptoms like stomach pain, feeling sick, throwing up, constipation, inability to pass gas, and bloating as it stops normal digestion. Blockages in the small intestines are more common than ones in the large intestines and are a frequent reason for surgeries on the small intestines. There are three types of bowel obstructions: partial blockages, complete blockages, or a ‘closed loop.’ A ‘closed loop’ obstruction means that the blockage happens at two spots on the same section of the intestine.

What Causes Bowel Obstruction?

There are numerous causes behind the blockage of the small or large intestines, which can be grouped into three categories: extrinsic, intrinsic, or intraluminal. Extrinsic causes, which come from outside the bowel, are the most common in developed countries. An example of an extrinsic cause is post-surgical adhesions, or scar tissue, that can make the bowel kink and block up. About two-thirds of people who’ve had abdominal surgery have these adhesions. Other typical extrinsic causes include cancer, which can compress the small bowel, causing a blockage. Hernias, both inguinal and umbilical, are less common, but still usual extrinsic causes. If not treated, hernias can cause the bowel to kink and become trapped, leading to a blockage and possibly a surgical emergency if the trapped bowel starts to lose its blood supply.

Intrinsic causes involve issues with the bowel itself. These can lead to gradual thickening of the bowel wall, which can cause a narrowing or stricture. Crohn’s disease is a common cause of benign strictures in adults.

On the other hand, intraluminal causes are less common. This usually happens when a swallowed object blocks the bowel or gets stuck in the ileocecal valve, preventing it from passing into the large intestine. But most foreign objects that make it past the pyloric sphincter, the entrance to the stomach, will also pass through the rest of the digestive tract without causing a blockage. Large bowel obstructions are even less common, making up only 10% to 15% of all intestinal blockages. The most common causes are adenocarcinoma, diverticulitis, and volvulus, with the sigmoid colon often the most affected part of the colon.

Risk Factors and Frequency for Bowel Obstruction

Small and large bowel obstructions occur equally in both men and women. There are certain risk factors that can impact how often they occur and who they affect. These include:

• Having had previous abdominal surgery
• Having colon or cancer that has spread to other parts of the body
• Having a chronic digestive disease
• Having an existing hernia in the abdominal wall or groin region
• Having been exposed to radiation therapy in the past
• Having swallowed a foreign object

Signs and Symptoms of Bowel Obstruction

If you suspect a bowel obstruction, a detailed medical history is needed, focusing on factors closely associated with bowel obstruction. Small bowel obstruction and large bowel obstruction often have similar symptoms, though they can differ in quality, timing, and how they present.

In small bowel obstruction, abdominal pain is often on and off and cramping, but it can get better when you vomit. Vomiting tends to happen more often, be in larger amounts, and have a green or yellow color. There’s also usually tenderness that’s limited to a specific area of the abdomen. However, in a large bowel obstruction, the pain is continuous and doesn’t come and go. The vomiting is not as frequent, may appear to contain fecal matter, and tenderness is spread out wide across the abdomen. Also, large bowel obstruction can cause significant bloating and constipation.

It’s also important to note that sometimes a large bowel obstruction can look like a small bowel obstruction if the ileocecal valve, which separates the small and large intestines, doesn’t work properly. This can cause air to get from the large bowel into the small bowel, creating symptoms of a small bowel obstruction.

Testing for Bowel Obstruction

If a doctor suspects a patient has a bowel obstruction, simply learning about their symptoms and medical history may not be enough for a firm diagnosis. Therefore, it is typically necessary to order an abdominal CT scan with an orally-administered contrast agent. CT scans can help doctors see the precise point of obstruction, understand how severe it is, identify the cause of the obstruction, and check for any serious complications such as infection or rupture. These insights help doctors identify patients who may need surgery to deal with their obstruction.

Lab tests are also essential to determine any imbalances in the patient’s electrolyte levels that could be caused by vomiting, which is a common symptom of bowel obstruction. Lab tests also check for an increased lactic acid level, which can indicate the presence of sepsis (a severe infection) or a perforation (a hole in the bowel). However, it’s important to realize that even if there is a perforation, the lactic acid level in the blood might still appear normal initially.

A physical exam is also a critical part of the diagnostic process, as it can offer clues about how severe the patient’s condition is and whether they need immediate surgery or can be managed with medication and other nonsurgical treatments.

Treatment Options for Bowel Obstruction

The first step in handling a patient’s condition is to check their breathing, heartbeat, and whether they can open their mouth and talk. If the patient needs immediate help, they will be given a saline solution and needed electrolytes. A special tube, a Foley catheter, will be put in place to keep track of how much the patient is peeing if they are in a precarious or critically ill condition. To help remove swelling from the blocked part of the patient’s intestines, and to prevent the risk of food aspiration, a nasal tube insertion, which goes from the nose to the stomach, will be performed.

The type of treatment a patient receives depends on the cause and seriousness of their blockage. If the patient is stable and blockage is partial or not severe, using a nasal tube and other supportive measures should be sufficient. If a patient arrives with a hernia that can be pushed back inside, they’ll need surgery at a later date to prevent it from happening again. However, inflamed hernias that cannot be pushed back inside need immediate surgical intervention.

Cases of complete or severe obstruction often require urgent surgery as these situations raise the risk of inadequate blood supply to organs. Chronic illnesses, like Crohn’s disease and cancer, need initial supportive measures and long periods of non-surgical intervention. Ultimately, the patient’s health condition and the surgeon’s judgment will guide the course of treatment.

What else can Bowel Obstruction be?

• Abdominal hernias
• Belly pain in seniors
• Appendicitis: inflammation of a small pouch-like organ in your belly
• Chronic megacolon: a long-term condition where the colon becomes larger than normal
• Polyps in the colon: small growths in the large intestine
• Diverticulitis: infection or inflammation of small pouches that can form in your digestive tract, especially in the lower parts
• Diverticulitis empiric therapy: treatment for diverticulitis based on doctor’s judgment and past experiences
• Surgery for pseudomembranous colitis: an operation to treat a type of inflammation in the large intestine that occurs after antibiotic use
• Small bowel obstruction: a blockage in the small intestine
• Toxic megacolon: a severe form of megacolon where the large intestine abruptly expands

What to expect with Bowel Obstruction

The results are generally positive when a bowel obstruction is handled quickly. Traditionally, patients treated without surgery are more likely to experience repeated episodes of bowel obstruction than those treated with surgery.

Possible Complications When Diagnosed with Bowel Obstruction

Possible Complications Include:

• Internal abdominal abscess
• Sepsis, a severe infection that effects the entire body
• Disability
• Wound separation after surgery
• Accidentally breathing in foreign objects (aspiration)
• Short bowel syndrome, a condition caused by the small intestine not being long enough
• Pneumonia, a lung infection
• Bowel perforation, a hole in the wall of the bowel
• Respiratory failure, when the lungs fail to get enough oxygen to the blood
• Anastomotic leak, a leak between two sections of the bowel that were stitched together after surgery
• Renal failure, when the kidneys can’t filter waste from the blood
• Death

Recovery from Bowel Obstruction

Generally, recovery after surgery for bowel obstruction takes time. It’s important for these patients to be given preventative treatment for deep vein clots and to avoid lung collapse. Getting up and moving around is crucial. Depending on the severity of the condition, the timeline for when they can start eating again might differ.