Intestinal Obstruction: Symptoms, Types, Causes and Treatment

Intestinal obstruction is a serious and often urgent medical condition where the normal movement of the contents through the intestines is blocked. Whether the result of mechanical barriers, functional disturbances, or systemic disease, intestinal obstruction can be life-threatening if not recognized and managed promptly. In this article, we explore the symptoms, types, causes, and treatments of intestinal obstruction, synthesizing up-to-date evidence to provide a clear, actionable overview.

Symptoms of Intestinal Obstruction

Recognizing the symptoms of intestinal obstruction is crucial for early diagnosis and intervention. The symptoms can sometimes be subtle, but more often they are dramatic and alarming, reflecting the body’s struggle as the intestinal tract becomes blocked.

Symptom	Description	Commonality	Source(s)
Abdominal Pain	Cramping, colicky, or persistent discomfort	Very common	2 3 4 5 6
Vomiting	Often profuse; may become feculent in late stages	Common	2 3 4 5 6
Distension	Swelling/bloating of abdomen	Common	2 3 4 5 6
Constipation	Inability to pass stool or flatus	Common	2 3 4 5 6
Nausea	Often precedes vomiting	Common	2 3 4 5 6
High-pitched Bowel Sounds	Audible on physical exam	Suggestive	2 3 4
Tympany	Drum-like sound on abdominal percussion	Suggestive	2 3 4
Diarrhea	Occasionally present, especially early or in partial obstruction	Less common	1 9
Urinary Symptoms	May occur in pseudo-obstruction	Uncommon	1

Table 1: Key Symptoms

Abdominal Pain

Abdominal pain is the hallmark symptom and can vary from mild cramping to severe, colicky pain. It often comes in waves, reflecting peristaltic efforts to overcome the blockage. However, as the obstruction persists, pain may become constant and more severe—especially if complications like strangulation or perforation occur 2 3 4 5 6.

Vomiting and Nausea

Vomiting is another prominent feature, particularly in obstructions higher in the intestine. The vomitus may start as stomach contents but can become bilious or even feculent as the blockage persists and the bowel dilates 2 3 4 5 6. Nausea frequently accompanies vomiting.

Distension and Constipation

The abdomen often becomes visibly swollen (distended), especially in lower or complete obstructions. Constipation, specifically the inability to pass flatus (gas) or stool, is a classic finding, though partial obstructions may still allow some passage 2 3 4 5 6.

Physical Examination Findings

Physicians often note high-pitched, "tinkling" bowel sounds upon auscultation and tympany on percussion—both are clues to the diagnosis. In advanced cases, bowel sounds may decrease, indicating bowel fatigue or necrosis 2 3 4.

Other Symptoms

Some patients, especially those with chronic or pseudo-obstruction, may experience diarrhea, weight loss, or even urinary symptoms due to associated bladder dysfunction 1 9.

Types of Intestinal Obstruction

Understanding the different types of intestinal obstruction helps guide diagnosis and management. Obstructions are generally classified based on their mechanism and anatomical location.

Type	Mechanism	Typical Features	Source(s)
Mechanical	Physical blockage	Sudden onset, severe	2 3 4 5 6
Functional	Motility disorder, no physical block	Chronic, subtle	1 7 9
Small Bowel	Blockage in small intestine	Rapid symptoms	4 5 6 8 11
Large Bowel	Blockage in colon	Gradual symptoms	4 6 8 11
Pseudo-obstruction	Looks obstructive, but no blockage	Recurrent, systemic	1 7 9

Table 2: Types of Intestinal Obstruction

Mechanical Obstruction

Mechanical obstruction is caused by a physical barrier in the intestines. It may be complete or partial and is usually acute in onset. Common examples include adhesions, hernias, tumors, volvulus (twisting), and intussusception 2 3 4 5 6.

• Small Bowel Obstruction (SBO): More common than large bowel obstruction. Symptoms develop rapidly and are often more severe 4 5 6 8 11.
• Large Bowel Obstruction (LBO): Typically develops more gradually and is most often due to malignancy or volvulus 4 6 8 11.

Functional Obstruction (Paralytic Ileus and Pseudo-obstruction)

In functional obstruction, there is no physical blockage. Instead, the bowel fails to propel its contents forward due to a motility disorder.

• Paralytic Ileus: Often occurs after surgery, infections, or metabolic disturbances. The bowel is inactive, leading to distension and symptoms similar to mechanical obstruction 7.
• Chronic Intestinal Pseudo-obstruction (CIPO): A rare disorder mimicking true obstruction but due to severe motility dysfunction. It can be idiopathic or secondary to systemic diseases 1 7 9.

Pseudo-obstruction

Pseudo-obstruction can be acute or chronic. Chronic idiopathic pseudo-obstruction presents with recurrent symptoms over months or years and is associated with underlying neuropathies, myopathies, or mesenchymopathies 1 7 9.

Causes of Intestinal Obstruction

The causes of intestinal obstruction are diverse and vary by age, geography, and clinical setting. Understanding the common and rare causes is vital for accurate diagnosis.

Cause	Description	Prevalence/Notes	Source(s)
Adhesions	Scar tissue post-surgery	Most common in adults	2 3 5 6 13
Hernias	Protrusion of bowel through a weak spot	Common globally	5 6 11
Malignancy	Tumors causing blockage	More common in elderly	2 3 4 6 10
Volvulus	Twisting of bowel	Sigmoid/cecal common	6 8 11
Intussusception	Telescoping of bowel (esp. children)	Pediatric cause	8 12
Congenital Bands	Abnormal bands causing compression	Pediatric, rare	12
Fecal Impaction	Hard stool causing blockage	Elderly, immobile	6
Gallstone Ileus	Gallstone occludes bowel	Rare, elderly	11
Pseudo-obstruction	Motility failure, no block	Rare, chronic	1 7 9
Gynecologic Causes	Post-op adhesions, tumors	Females, post-surgery	13

Table 3: Main Causes of Intestinal Obstruction

Adhesions

Adhesions, or bands of scar tissue, are the leading cause of small bowel obstruction in developed countries, especially after abdominal or pelvic surgery. They can form after any intra-abdominal operation, including gynecologic procedures 2 3 5 6 13.

Hernias

Hernias—especially inguinal and femoral—are a major cause worldwide, particularly in regions where elective hernia repair is less common. They can trap the intestine, leading to strangulation and obstruction 5 6 11.

Malignancy

Cancer is the predominant cause of large bowel obstruction, especially colorectal tumors. Obstruction can also occur from metastatic disease or tumor recurrence after prior surgery 2 3 4 6 10.

Volvulus and Intussusception

• Volvulus: Twisting of the intestine, commonly seen in the sigmoid colon or cecum, leading to rapid obstruction and risk of ischemia 6 8 11.
• Intussusception: More common in children, where a segment of bowel telescopes into another, rapidly causing obstruction 8 12.

Rare and Other Causes

• Congenital Bands: Abnormal tissue bands, rare but important in pediatric cases 12.
• Fecal Impaction: Particularly in the elderly or chronically bed-bound 6.
• Gallstone Ileus: Rare, usually in older adults 11.

Functional and Pseudo-obstruction

Functional causes, including chronic idiopathic pseudo-obstruction, represent a failure of motility rather than a true blockage and may be seen in both children and adults. They are challenging to diagnose and manage 1 7 9.

Gynecologic Factors

Adhesions related to gynecologic surgery (e.g., hysterectomy, myomectomy) and pelvic tumors are significant contributors in women 13.

Treatment of Intestinal Obstruction

Treatment strategies depend on the type, cause, severity, and presence of complications. Prompt intervention can be life-saving, especially in cases with strangulation or perforation.

Treatment	Approach	Indication/Notes	Source(s)
Fluid Resuscitation	IV fluids to correct deficit	All obstructions	2 3 4 16
Bowel Rest	Nothing by mouth	All obstructions	2 3 4
Decompression	NG tube, occasionally venting gastrostomy	Severe distension	2 3 4 10 16
Surgery	Resection, release of block, stoma	Strangulation, failed conservative	2 3 4 5 6 8 14 15
Antibiotics	IV, gram-negative/anaerobic coverage	Perforation, sepsis	3 4
Stenting	Endoscopic stents for tumors	Malignant LBO	16
Medications	Analgesics, antiemetics, somatostatin analogues	Symptom control	16
Nutritional Support	Parenteral or enteral nutrition	Chronic, severe cases	7 9 16
Laparoscopy	Minimally invasive surgery	Selected patients	14

Table 4: Treatment Approaches

Initial Management

The first steps are stabilization and supportive care:

• IV fluid resuscitation is essential to correct dehydration and electrolyte imbalances caused by vomiting and third-spacing of fluids into the obstructed bowel 2 3 4 16.
• Bowel rest (NPO: nothing by mouth) is recommended, with nasogastric (NG) tube decompression to relieve vomiting and abdominal distension 2 3 4 10.

Non-Surgical Treatment

Many uncomplicated obstructions—especially those caused by adhesions—can resolve with conservative management:

• Nasogastric decompression is often effective; persistent symptoms beyond 3 days suggest the need for surgery 2 3 4 10.
• Antibiotics if there are signs of infection, fever, or suspected perforation 3 4.
• Medications such as antiemetics, analgesics, and somatostatin analogues can help control symptoms, particularly in inoperable malignant obstructions 16.

Surgical Intervention

Surgery is indicated for:

• Failure of conservative management (no improvement within 48-72 hours)
• Signs of bowel ischemia or perforation (tachycardia, fever, leukocytosis, peritonitis)
• Strangulated hernias, volvulus, tumors not amenable to stenting 2 3 4 5 6 8 14 15

Surgical options include:

• Adhesiolysis (removing adhesions)
• Resection of necrotic or tumor-containing bowel
• Stoma creation (colostomy, ileostomy)
• Laparoscopy is increasingly used for diagnosis and treatment, offering quicker recovery and fewer complications in selected patients 14.

Special Situations

• Malignant Obstruction: May be managed with stenting or palliative surgery, but outcomes are variable. Non-surgical management is often prioritized in advanced cancer 15 16.
• Chronic Pseudo-obstruction: Management is challenging; includes nutritional support, prokinetic drugs, and rarely, surgery 7 9.

Nutritional and Symptom Support

Patients with chronic or severe obstruction may require parenteral nutrition, ongoing fluid management, and multidisciplinary care to address pain, nutritional deficits, and quality of life 7 9 16.

Conclusion

Intestinal obstruction is a complex clinical challenge, requiring rapid recognition and tailored management. Key takeaways include:

• Classic symptoms include abdominal pain, vomiting, distension, and constipation; early recognition is vital 2 3 4 5 6.
• Types include mechanical (most common), functional (pseudo-obstruction), and can occur in the small or large bowel 2 3 4 5 6 7 9 11.
• Common causes are adhesions, hernias, malignancies, volvulus, intussusception, and in some cases, motility disorders 2 3 4 5 6 7 9 11 13.
• Treatment starts with supportive care and bowel rest; surgery is reserved for complications or failed conservative therapy 2 3 4 5 6 8 14 15 16.
• Special management is needed for chronic pseudo-obstruction and malignant cases, including multidisciplinary and palliative approaches 7 9 15 16.

Prompt diagnosis, vigilant monitoring, and individualized treatment are essential to improving outcomes in patients with intestinal obstruction.