Bowel obstruction – Signs and symptoms

A bowel obstruction is a dangerous emergency and requires quick clarification. Acute abdominal pain accounts for almost ten percent of all visits to the emergency room. However, very few patients have an acute bowel obstruction that requires surgery. This article explains the most common causes and the typical symptoms of this clinical picture. Two separate sections deal with the disease mechanisms and symptoms in young children.

What is an intestinal obstruction/bowel obstruction?

In an intestinal obstruction (ileus), the leftover food and other body fluids can no longer be removed from the intestine. The disturbance in the intestinal passage can have various causes. Doctors distinguish two mechanisms of origin:

1. Mechanical bowel obstruction, due to constipation from the inside or a narrowing of the intestine from the outside
2. Functional bowel obstruction, where there is no space problem causing the symptoms, but nerve damage paralyzes the intestinal muscles

How do mechanical and functional intestinal obstructions arise?

Mechanical bowel obstruction

A mechanical obstacle blocks the passage of intestinal contents through a narrow space. Possible causes are:

• Adhesions after operations (Bridenileus)
• Tumors
• Thickening of the intestinal wall, such as sigmoid diverticulitis
• Malformations of the intestine
• Coprostasis
• Gallstones
• Parasites
• Hernias
• Intestinal invagination
• Intestinal torsion

If blood flow to the intestine is no longer possible, intestinal vessels are pinched off. This is called "Strangulation". Intestinal occlusion without vascular constriction is simply an "obstruction". According to a gastroscopy an intestinal occlusion is the cause of a strangulation / bridging ileus in 80 percent of cases. If no gastroscopy has been performed, then an intestinal tumor is the cause of a closure in 70 percent of cases. The colon is mostly affected here.

Functional bowel obstruction

The nerve cells no longer activate the intestinal muscle cells. Then the intestine is paralyzed and can no longer work and digest. Possible causes are:

• Occlusions
• Inflammation of abdominal organs, such as appendicitis or inflammation of the gallbladder
• Trauma
• Surgery or abdominal mirroring
• Metabolic diseases such as diabetes mellitus
• Medicines such as opioids or antidepressants

How does bowel obstruction cause symptoms?

In both forms of intestinal obstruction, intestinal contents build up and cause complaints.

Upper small intestine

In the event of a congestion in the uppermost section of the intestine, the patient loses a lot of fluid and electrolytes. The blood volume drops and the kidney fails. During the treatment, the doctor provides liquid to the patient again, so that this problem can be solved quite well. The mortality rate is low.

Deep small intestine and large intestine

In the case of a stasis of lower intestinal sections, bacterial overgrowth is the main cause of the symptoms. The bacteria release toxins that attack the intestinal mucosa and trigger inflammatory processes. In severe cases, the bacteria break through the intestine and get into the abdominal cavity or lymph nodes (peritonitis through migration). Another factor in the colon obstruction is the stretching of the intestinal wall (distension), which increases the pressure in the abdominal cavity. As a result, blood flow to the heart drops. In addition, the diaphragm slides up and makes breathing difficult.

What are the symptoms of bowel obstruction?

The symptoms are unfortunately unspecific, so that an exact organ allocation is often not possible. If other causes have been excluded and there are only stomach symptoms, this indicates the upper digestive tract. A bowel obstruction of the lower digestive tract is more characterized by constipation. Other typical symptoms with bowel obstruction include:

• Nausea
• Vomiting
• Stomach pain
• Feeling of fullness
• Flatulence
• Diarrhea
• Constipation
• Bloating
• Burping
• Burning behind the breastbone
• Premature saturation
• Weight loss

What conclusions can be drawn about the location and cause based on the symptoms?

The symptoms can occur individually or overlap. The severity of the symptoms does not allow a reliable conclusion to be drawn about the underlying cause. In general, the worse the symptoms, the more advanced the closure. A distinction between mechanical and functional intestinal obstruction is difficult based on the symptoms alone. The demarcation from irritable bowel syndrome is also not possible without further diagnosis. The following table presents some intestinal occlusion locations and causes with their characteristic symptoms.

How common are adhesions after abdominal surgery?

Scarred adhesions occur in up to 95 percent of patients with open abdominal surgery. Most adhesions are symptom-free and have no effect on the patient. In the worst case, the adhesions can lead to intestinal obstruction. The risk of such a complication is significantly lower with abdominal mirroring. It is known from gynecology that about three percent of patients with interventions on the abdominal cavity have adhesions that lead to a new hospital stay.

What types of bowel obstruction occur in young children?

Invagination

Invagination describes the indentation of a section of the intestine into the underlying section of the intestine. The intestinal walls slide over one another and pinch off intestinal vessels. In 80 percent of the cases, the children are under one year old. The causes are viral infections, bulges of the intestine (Meckel diverticula), bleeding, foreign bodies or masses. Repeated invaginations up to the twelfth age occur in children with cystic fibrosis.

Volvulus

A volvulus is a spontaneous twisting of intestinal sections that is hung in the abdomen. The volvulus pinches off important intestinal vessels. Two mechanisms of origin can be differentiated:

1. The intestinal loops are extremely flexible: The small intestine is suspended from a tissue structure that is poorly fixed in some people. So the intestine can twist.
2. Adhesive strands after inflammation or surgery: The strands are like enlarged scars that cause the bowel to twist.

This occurs both in infants and in children during puberty. Sometimes the twist resolves itself.

Hirschsprung's disease

In this congenital malformation, important nerve cells are not attached to the large intestine. Hirschsprung’s disease is therefore also referred to as aganglionosis. The newborn cannot excrete feces after birth., The disease is probably genetic. Ten percent of the patients are premature babies. The symptoms often appear immediately after birth in the first days of life. In some cases, the symptoms only appear with the change of food after the newborn period.

What are the symptoms in babies?

A baby cannot verbalize the abdominal pain. With a classic bowel obstruction, the children scream continuously. Symptom-free intervals are also possible with the invagination. Indications for an intestinal obstruction in babies include:

• Sudden onset cramping abdominal pain with strong screaming
• Bilious vomiting
• Protective posture with tightening of legs

Additionally for invagination:

• Painless phases
• Bloody-slimy stool ("raspberry jelly-like")
• Palpable structure on the abdomen

Additionally with volvulus:

• Crawling position with knee and elbow support reduces pain

Additionally with Hirschsprung's disease:

• Late departure of meconium
• Intestinal inflammation in the newborn period
• Failure to thrive
• Explosive defecation after examining the rectum

When to see a doctor

Any form of intestinal obstruction is an absolute emergency.

If you suspect a bowel obstruction, a doctor should always be contacted as soon as possible!