What is the management approach for a patient with a thickened bowel loop?

Management of Thickened Bowel Loop

Obtain contrast-enhanced CT enterography immediately to determine the underlying cause, assess for surgical emergencies (perforation, closed-loop obstruction, ischemia), and guide definitive management. 1

Initial Clinical Assessment

Immediately evaluate for signs requiring emergency surgery:

• Peritoneal signs on examination (rebound tenderness, guarding, rigidity) mandate immediate surgical exploration 2, 1
• Hemodynamic instability (hypotension, tachycardia) suggests bowel ischemia or perforation requiring urgent intervention 2
• Fever with leukocytosis and left shift indicates possible sepsis from perforation or ischemia 1

Obtain critical laboratory studies:

• Complete blood count looking for leukocytosis with left shift 1
• C-reactive protein and lactate—elevated levels strongly suggest peritonitis or bowel ischemia 1
• Electrolytes, BUN/creatinine, and coagulation profile 3

Imaging Strategy

CT enterography with IV contrast is the gold standard with 87-90% accuracy for determining etiology and should be performed immediately in all patients 1. This triple-phase study (non-contrast, arterial, portal venous) identifies the underlying cause, evaluates for complications, and excludes other diagnoses 2.

Key CT findings that determine management:

• Focal, irregular, asymmetric thickening suggests malignancy requiring oncologic workup 4
• Symmetric thickening with disproportionate fat stranding indicates inflammatory conditions like Crohn's disease 4
• Multilayered mural stratification (Type A pattern) or strong mucosal enhancement with prominent low-density submucosa (Type B pattern) indicates acute inflammatory disease 5
• Homogeneous enhancement (Type D pattern) suggests quiescent disease 5

MR enterography is preferred over CT in young patients requiring serial monitoring, pregnant patients, or when multiparametric assessment is needed to avoid radiation exposure 1. MRI has 78% sensitivity and 85% specificity compared to endoscopy 2.

Ultrasound can identify thickened bowel loops, assess peristalsis, and detect free fluid or abscesses in skilled hands, but should not replace CT/MRI for definitive diagnosis 2, 1.

Immediate Surgical Indications

Proceed directly to emergency surgery if any of the following are present:

• Free perforation with pneumoperitoneum and free fluid 2, 3
• Closed-loop obstruction on CT (U-shaped distended loop with abrupt transition) 6, 7
• Bowel ischemia evidenced by pneumatosis, portal venous gas, or lack of wall enhancement 2
• Clinical peritonitis on examination 2, 1
• Hemodynamic instability despite resuscitation 2
• Massive life-threatening hemorrhage 2

Etiology-Specific Management

Small Bowel Obstruction

Initial non-operative management is appropriate for patients without peritoneal signs, strangulation, or ischemia 3. This includes:

• NPO status with nasogastric decompression 3
• Fluid resuscitation with crystalloids and electrolyte correction 3
• Water-soluble contrast administration (diagnostic and therapeutic) 3

Surgery is indicated if:

• No improvement after 72 hours of conservative management 3
• Large amount of free fluid between dilated loops on ultrasound suggests high-grade obstruction requiring immediate surgery 8
• CT enteroclysis may be needed for suspected intermittent or low-grade obstruction with sensitivity of 48-50% for standard CT 2

Inflammatory Bowel Disease (Crohn's Disease)

Cross-sectional imaging is mandatory before scheduling surgery to assess disease location, extent, and complications 2. Recent ileocolonoscopy should also be reviewed 2.

Medical management first for patients with active inflammation showing multilayered enhancement pattern on CT 5. Bowel wall thickness ≥4mm with decreased compressibility, narrowing, and extramural lesions are diagnostic features 2.

Surgery is preferred for localized ileocecal disease with obstructive symptoms but no significant active inflammation 2. In perforating/fistulizing disease, surgery should be considered early due to higher risk of medical treatment failure 2.

Faecal calprotectin has 95% sensitivity and 91% specificity for differentiating IBD from non-IBD diagnoses, with optimal cut-off of 100 μg/g 2.

Acute Severe Ulcerative Colitis

Multidisciplinary evaluation with gastroenterology for hemodynamically stable patients to decide initial medical treatment 2.

Emergency subtotal colectomy with ileostomy is indicated for:

• No improvement or deterioration within 48-72 hours of medical therapy 2
• Failure of second-line therapy 2
• Massive colorectal hemorrhage in unstable patients 2
• Toxic megacolon with no improvement after 24-48 hours 2

Mesenteric Ischemia

Arterial embolism (most common cause) presents with sudden severe pain and atrial fibrillation history. CT shows occlusive filling defect in proximal SMA with thickened, edematous, dilated bowel 2.

Endovascular aspiration embolectomy should be attempted first with technical success rates up to 94%, lower morbidity, and lower bowel resection rates compared to open surgery 2. However, up to 70% may still need surgical intervention for bowel resection 2.

Common Pitfalls to Avoid

• Do not delay surgery in patients with peritoneal signs while pursuing additional imaging—clinical examination trumps imaging 2, 1
• Do not assume normal CRP excludes active disease—approximately 20% of patients with active Crohn's disease have normal CRP levels 2
• Do not perform colonoscopy in moderate-to-severe disease due to higher perforation risk; flexible sigmoidoscopy is safer 2
• Do not miss closed-loop obstruction—look specifically for U-shaped distended fluid-filled loop with abrupt transition, as plain films may be unremarkable 6, 7
• Consider tuberculosis, Behçet's, lymphoma, and vasculitis in the differential for ileal thickening, especially in appropriate clinical contexts 2, 1