Classification
- Open vs Closed
- Incomplete vs Complete
- Extrinsic (tumor, volvulus, adhesions, hernias) vs Intramural (tumor, stricture, Crohn’s, ischemia) vs Intraluminal (constipation, FB, bezoar – tricho, phyto)
- Small bowel vs Large bowel
Differential Diagnosis of a Small Bowel Obstruction
- Adhesions
- Hernias
- Neoplasm (Adenocarcinoma, Carcinoid)
- Inflammatory bowel disease, Volvulus, Intussusception, Gallstone ileus, Bezoars
Differential diagnosis of a large bowel obstruction (usually sigmoid)
- Carcinoma
- Diverticulitis
- Volvulus
- IBD, Radiation, Intussusception, Olgilvie’s, Paralytic ileus, Metabolic ileus, Drugs
History
- Presentation: obstipation, nausea and vomitting, cramping, distension, typanism, dehydration, tinkling bowel sounds, pain, visible peristalsis
- Last meal
- B symptoms: fevers, night sweats, weight loss
- PMHx – previous surgeries, diet (high fibre, high bulk = volvulus), inflammatory bowel disease, tumors, bleeding problems, hernias
- Medications
- Family history – cancer, bleeding
- Social history– smoking, EtOH
Physical exam
- Vitals (if dehydrated – tachycardia, postural hypotension, low urine output)
- Inspection: distension, visible peristalsis
- Percussion: tympanic, pain
- Palpation: masses, distension, pain (complicated)
- Auscultation: loud Borborygmus (tinkling), lack of bowel sounds
Labs
- CBCD, lytes, BUN, Cr
- Beta HCG
- Amylase, Lipase
- Low sodium
- Low potassium
- Low volume
- WBC if strangulated
- Metabolic alkalosis with vomiting (hypokalemic, hypochloremic)
Imaging
- Abdominal x-rays
- Great Big FART
- Gas pattern
- Bowel wall air
- Free air
- Air fluid levels
- Air in Rectum
- Thickened bowel wall
- 60% will be normal
- upright chest x-ray or left lateral decubitus to rule out free air
- No air in rectum and many air fluid levels
- If ischemic look for free air, pneumatosis, thicked bowel wall, air in portal vein
- No air in RLQ, bubble in LUQ – cecal volvulus
- Omega or kidney bean in RLQ with bird’s beak – sigmoid volvulus
- Double bubble – duodenal atresia
- Air in biliary tree plus SBO – gallstone ileus
- Cecum >12cm, Transverse colon >6cm, SB >5cm –> OR
- Great Big FART
- Ultrasound – for closed loop
- CT – for questionable patients
- Contrast studies – enema, not from above!
Do not take to OR if:
- Post-op
- Carcinomatosis
- Recurrent adhesive bowel obstruction
- Post radiotherapy
Treatment
- Stabilize vitals, fluid and electrolyte resuscitation
- NG tube
- Foley catheter to monitor in/outs
- Manage conservatively if partial – take to OR if does not resolve
- If strangulated/complicated – to OR
Orders
- NPO, ice chips
- AAT
- Vitals q2h
- IV Ringer’s lactate bolus 500cc-2000cc then run at 150cc/hr
- CBCD, lytes, BUN, Cr, amylase, lipase
- Abdominal x-ray 3 views, repeat in 8 hrs
- NG to gravity or low suction
- Foley to urometer
- Ins/Outs q1hr, call if <60cc over 2 hr
- Flagyl 500mg IV on call to OR
- Ancef 1g IV on call to OR