Understanding Bowel Obstruction Types and Symptoms

• Bowel obstruction happens when contents can't pass through the intestines
• It can happen in the small bowel (SBO) or large bowel (LBO)
• Bowel obstruction can be partial, complete, simple, or strangulated

Types of Bowel Obstruction

• Mechanical obstructions are physical
• Most obstructions happen in the small intestine
• Surgical adhesions are a common cause of SBO
• Other causes of SBO: hernias, cancer, strictures from Crohn's disease, intussusception
• CRC and diverticular disease can cause LBO
• Adhesions, ischemia, volvulus, and Crohn's are other causes of LBO

Intussusception

• Exact cause is unknown, but more common in children
• Often happens after a virus causes swelling of the intestinal lining, leading it to slip into itself

Symptoms of Intussusception

• In children:

  • Sudden, loud crying
  • Infants pull knees to their chest
  • Pain comes and goes
  • Red, currant jelly-like stools mixed with blood and mucous
  • Vomiting, palpable lump in the abdomen, lethargy, diarrhea, fever

• In adults:

  • Rare
  • Pain comes and goes
  • Nausea/vomiting may occur
  • Causes in adults are usually surgery, polyp or tumor, adhesions, Crohn's disease

• Nonmechanical obstructions are due to reduced or absent peristalsis

• Often caused by altered neuromuscular parasympathetic innervation

• Neuromuscular or vascular disorders can cause it

• Paralytic ileus is a type of nonmechanical obstruction

• It involves lack of intestinal peristalsis and bowel sounds

• Paralytic ileus is the most common form of nonmechanical obstruction

• Abdominal surgery, peritonitis, inflammatory disorders, electrolyte imbalances, or spinal fractures can induce it

Rare Types of Intestinal Obstruction

• Pseudo-obstruction: mimics mechanical obstruction
• Rare GI motility disorder
• Not visible on imaging
• Neuro conditions, drugs, endocrine and metabolic problems, lung disease, trauma, and burns can cause it
• Vascular obstruction: emboli or thrombi alter blood supply to part of the intestines

Consequences of Intestinal Obstruction

• Intestinal obstruction can be life threatening
• In a proximal bowel obstruction:
  • Accumulation of fluid, gas, and intestinal contents occurs
  • Distention occures
  • Increased pressure in the bowel lumen results
  • Capillary permeability increases
  • Extravasation of fluids and electrolytes into the peritoneal cavity occures
  • Intestinal muscle fatigue and slowed peristalsis happen
  • Decreased circulating blood volume occurs

Clinical Manifestations by Location

• Small intestine obstruction symptoms:
  • Acute onset
  • Crampy, colicky, intermittent pain
  • Early, profuse, and biliary vomiting
  • Greatly increased abdominal distention
  • Presence of feces for a short time
  • Rapid loss of Cl, K, and Na electrolytes
• Large intestine obstruction symptoms:
  • Slow, insidious onset
  • Less intense, vague, mild or sharp/severe pain depending on the cause
  • Late, feculent vomiting (may be absent)
  • Increased abdominal distention
  • Absolute constipation (lack of flatus)
• Late electrolyte imbalance is more common

Diagnosis

• Diagnostic studies can be done
  • CT scan
  • Abdominal x-ray
  • Ultrasound
  • Sigmoidoscopy or colonoscopy
  • CBC, WBC, BUN

Management

• Treatment depends on the cause of the obstruction
• For almost all:
  • NPO (nothing by mouth)
  • Decompress the bowel by inserting NG tube
  • IV fluid therapy/monitor fluid balance is necessary
• Pain control and strict I&O monitoring occur
• Surgery is a last resort

Evaluate Care

• Improvement signs:
  • Return of bowel sounds/ passing gas
  • Passage of stool/similar stool patterns to baseline
  • Reduced nausea/vomiting
  • Less bloated feeling