### Date : 2024-11-19 16:59 ### Topic : Small Bowel Obstruction #gastroenterology ---- ### **Small Bowel Obstruction (SBO)** **Small bowel obstruction (SBO)** is a condition where the normal flow of intestinal contents is partially or completely blocked within the small intestine. It is a **common surgical emergency** and can lead to significant morbidity if untreated. --- ### **Pathophysiology** 1. **Mechanical Obstruction**: - A physical blockage prevents the passage of intestinal contents. - Proximal to the obstruction: - Accumulation of gas, fluid, and food. - Intestinal distension and increased intraluminal pressure. - Distal to the obstruction: - Intestine collapses due to lack of content flow. 2. **Complications**: - **Bowel wall ischemia** due to increased pressure reducing blood supply. - **Perforation** if ischemia or prolonged obstruction compromises the bowel wall. - **Bacterial translocation** leading to peritonitis and sepsis. 3. **Functional (Paralytic Ileus)**: - A non-mechanical failure of peristalsis without any physical blockage. --- ### **Etiology** #### **1. Mechanical Causes** - **Adhesions** (most common cause): - Postoperative scarring, especially after abdominal or pelvic surgeries. - **Hernias**: - Strangulated or incarcerated hernias can compress the bowel. - **Tumors**: - Intraluminal or extrinsic compression by malignancies. - **Intussusception**: - Telescoping of one part of the bowel into another. - **Volvulus**: - Twisting of the intestine on its mesentery. - **Foreign Bodies**: - Ingested objects, gallstones, or bezoars. - **Strictures**: - Due to Crohn’s disease, radiation, or ischemic injury. #### **2. Functional Causes** - **Paralytic Ileus**: - Postoperative state, electrolyte imbalance (e.g., hypokalemia), sepsis, or medications (e.g., opioids). --- ### **Clinical Features** 1. **Symptoms**: - **Abdominal Pain**: - Crampy and colicky, typically in waves. - **Vomiting**: - Proximal obstruction: Early, bilious vomiting. - Distal obstruction: Late, feculent vomiting. - **Abdominal Distension**: - More pronounced in distal obstructions. - **Constipation**: - Complete obstruction: Absolute constipation (no passage of stool or flatus). - Partial obstruction: May have some passage of stool or gas. 2. **Signs**: - **Visible peristalsis**: In thin patients, sometimes seen as wave-like movements. - **High-pitched bowel sounds**: - Early obstruction: Hyperactive, "tinkling" sounds. - Late or ischemia: Absent bowel sounds. 3. **Complications**: - **Ischemia and Necrosis**: - Severe, continuous pain and peritoneal signs (guarding, rigidity). - **Perforation**: - Leads to peritonitis with rebound tenderness and signs of sepsis. --- ### **Diagnosis** #### **1. Clinical Assessment** - History of prior surgeries (adhesions), hernias, or malignancy. - Physical examination findings such as distension and abnormal bowel sounds. #### **2. Imaging** - **Abdominal X-ray**: - Dilated small bowel loops (>3 cm). - Air-fluid levels on upright films. - Absence of gas in the distal bowel (complete obstruction). - **CT Scan**: - **Gold standard** for identifying the cause and severity of obstruction. - Can detect strangulation, ischemia, or tumors. - **Ultrasound**: - Useful in children or pregnant women, particularly for intussusception or hernias. #### **3. Laboratory Tests** - **CBC**: - Leukocytosis may indicate infection or ischemia. - **Electrolytes**: - Dehydration may cause hypokalemia, hyponatremia. - **Lactate**: - Elevated levels suggest bowel ischemia. --- ### **Management** #### **1. Initial Stabilization** - **Fluid Resuscitation**: - Correct dehydration and electrolyte imbalances with IV fluids (e.g., Ringer's lactate or normal saline). - **Nasogastric Tube (NGT)**: - Decompresses the stomach and relieves vomiting. - **Pain Management**: - Avoid opioids if possible, as they may worsen ileus. - **Antibiotics**: - Broad-spectrum antibiotics if perforation or strangulation is suspected. #### **2. Definitive Treatment** - **Non-Surgical Management**: - For partial obstructions or adhesions without signs of ischemia: - NPO (nothing by mouth), NGT decompression, and close monitoring. - **Surgical Intervention**: - Required for: - Complete obstruction. - Strangulated bowel (ischemia, necrosis). - Persistent symptoms despite conservative management. - Procedures include: - Adhesiolysis (for adhesions). - Resection of necrotic bowel. - Repair of hernias or removal of tumors. --- ### **Prognosis** - **Uncomplicated SBO**: - High recovery rates with prompt management. - **Complicated SBO**: - Increased morbidity and mortality due to ischemia, necrosis, or perforation. --- ### **Key Points** 1. **Small Bowel Obstruction (SBO)** is a common cause of abdominal pain and vomiting, often due to adhesions or hernias. 2. Symptoms include **colicky abdominal pain, vomiting, distension**, and constipation. 3. Diagnosis involves **abdominal X-ray** and **CT scan** to identify the cause and severity. 4. Management includes **fluid resuscitation, NGT decompression**, and surgery for complicated cases. 5. Early recognition and treatment are essential to prevent complications like bowel ischemia and perforation.### Reference: ### Connected Documents: -