1. Bowel Obstruction
Tad Kim, M.D.
Connie Lee, M.D.

2. Definitions Ileus = obstruction 2/2 dysfunctional motility of bowel
Mechanical obstruction = 85% SB, 15% large bowel
Simple obstruction
Closed loop obstruction
Strangulation

3. SBO: Etiology
Adhesion #1 (80-90% of SBO in pt’s w/prior abdominal surgery)
Hernia #2 overall - #1 cause of SBO in pts w/o prior abdominal surgery
Tumor
Abscess
Hematoma
Annular pancreas
SMA syndrome
Congenital lesions
Gallstone ileus
Intussusception
Foreign body (bezoars, worms, etc)
Meconium ileus
Malrotation

4. Colonic Obstruction: Etiology
Cancer #1 (60%)
Volvulus (sigmoid > cecum)
Adhesions
Hernia UC
Diverticulitis
Congenital lesions
Fecal impaction
Adynamic ileus
Hirschsprung’s
Meconium ileus
Foreign body

5. Age & DDx
Age matters!
Neonate: meconium ileus, Hirschsprung’s, malrotation, atresia
Child: intussusception, Hirschsprung’s
Adult: hernia, IBD, CA, diverticular disease
Elderly: CA, diverticular disease, Ogilvie’s
gast

6. History & DDx Proximal obstruction: early bilious vomiting, +flatus/BM
Distal obstruction: obstipation, distension, vomiting feculent material (2/2 bacterial overgrowth of SB contents)
Pain w/obstruction: begins as cramping pain, changes to continuous severe pain w/strangulation & peritonitis
PMHx: remember to ask about cardiac history (arrhythmias, prior MI, Afib - think about intestinal ischemia), IBD, gallstones, cancer
PSHx: remember to ask about ostomy output
Meds: narcotics (ileus), antipsychotics (ileus), diuretics (hypoK a/w ileus)
ROS: recent weight loss (CA, SMA syndrome)

7. PE Start with ABCs Look for surgical scars Bowel sounds
Distention: distal obstruction >> proximal
Localized tenderness: think peritonitis
Look for hernias/masses
Do a rectal exam

8. Labs WBC (nml in uncomplicated SBO) CBC (anemia w/CA) BMP (hypoK)
Alkalosis (a/w proximal obstruction)
Acidosis (a/w bowel infarction)
Amylase (may be elevated in SBO)

9. Studies Upright CXR: look for free air
Flat and upright/left lateral decubitus: look for dilated bowel loops, air-fluid levels
Note: if cecal diameter >12cm, there is a risk of perforation. At 12-14cm, the wall tension > perfusion pressure, increasing risk of necrosis
Barium enema
UGI series w/SB follow-through
CT scan

10. SBO: Management NPO, NGT, Foley, IVF Electrolyte replacement
Many partial obstructions will resolve
“Don’t let the sun set on a (complete) SBO”
Complete bowel obstruction w/concern for strangulation/perforation requires immediate operative intervention (resuscitate first)

11. A 72-year-old woman presented with a 2-day history of abdominal pain associated with nausea and vomiting
A 72-year-old woman presented with a 2-day history of abdominal pain associated with nausea and vomiting. Over the previous 10 years, she had had progressive Alzheimer's disease, requiring her to live in a long-term care facility. On physical examination, there were no abdominal scars or umbilical, inguinal, or femoral hernias. Laboratory tests revealed a normal white-cell count, and an abdominal radiologic examination was suggestive of a complete small-bowel obstruction (Panel A). Computed tomography showed small-bowel obstruction by an intraluminal mass (Panel B, arrow). This mass had a hyperdense periphery and an aerated core. During laparotomy, an enterotomy was performed and a plastic ball was found within the lumen. The ball was 4 cm in diameter and had a hard plastic layer and a soft core. Additional questioning did not reveal whether the ingestion had been voluntary or accidental or when it might have occurred. The patient had an uneventful recovery.
Dedouit F and Otal P. N Engl J Med 2008;358:1381

12. A 48-year-old healthy woman presented with anorexia of 2 days' duration and abdominal pain in the right lower quadrant
A 48-year-old healthy woman presented with anorexia of 2 days' duration and abdominal pain in the right lower quadrant. Since appendicitis was suspected, she underwent a laparoscopic examination. An inflamed mass was seen near the cecum, and diverticulitis was diagnosed. She was treated with bowel rest, fluids, and antimicrobial agents. Two days later, her symptoms worsened, with increased pain in the right lower quadrant, abdominal distention, and decreased bowel sounds. Abdominal radiography showed dilatation of the small intestine, suggestive of obstruction, in the supine position (Panel A) and the upright position (Panel B). An axial computed tomographic scan of the abdomen showed a pericecal internal hernia (Panel C, arrows). The patient underwent an exploratory laparotomy, resulting in lysis of an adhesion and bowel reduction; no bowel resection was required. Her recovery was rapid and uneventful. Pericecal hernias account for 13% of internal hernias. Most commonly, the herniated loop consists of an ileal segment protruding through a defect in the cecal mesentery and extending into the right paracolic gutter. If strangulation occurs, the associated mortality is high.
Liu K and Lin B. N Engl J Med 2007;356:1152

13. A 60-year-old woman presented to the outpatient clinic with vague abdominal discomfort that had developed over the previous several weeks
A 60-year-old woman presented to the outpatient clinic with vague abdominal discomfort that had developed over the previous several weeks. There was no abdominal tenderness. Laboratory evaluation was notable for the white-cell count, which included 1.8% eosinophils. Colonoscopy demonstrated a worm, which moved (video). The worm had a smooth, cream-colored surface and was 20 cm in length. It was removed with an endoscopic snare and identified as Ascaris lumbricoides. The patient was given mebendazole; she did not pass any additional worms. Typically, complications from A. lumbricoides are associated with mechanical obstruction, such as migration of a worm into the biliary tree or the development of a high worm burden in the intestinal lumen. In this case, the abdominal discomfort resolved after the worm was removed. At a 2-month follow-up visit, the patient remained healthy.
Jang M and Lee K. N Engl J Med 2008;358:e16

14. A 68-year-old man with alcoholic cirrhosis, portal hypertension, ascites, and an umbilical hernia presented to the emergency department after an episode of coughing that was followed by a rush of fluid and fat from the umbilicus
A 68-year-old man with alcoholic cirrhosis, portal hypertension, ascites, and an umbilical hernia presented to the emergency department after an episode of coughing that was followed by a rush of fluid and fat from the umbilicus. The patient reported no abdominal pain. He had tense ascites but was otherwise asymptomatic before the episode and had no history of abdominal surgery. Physical examination revealed scleral icterus, spider angiomata, a distended abdomen with a fluid wave, and a 4-cm segment of omentum protruding from the umbilicus and draining ascitic fluid. In the operating room, strangulated omentum was found and resected, and the umbilical defect was repaired. Umbilical hernias are common in patients with ascites and result from elevated intraabdominal pressure in association with defects in the anterior abdominal wall. In rare cases, umbilical hernias may rupture. Factors precipitating rupture include local trauma, coughing, vomiting, or esophagoscopy. Complications of rupture include evisceration, confinement, or strangulation of bowel, as well as hypotension due to fluid shifts or peritonitis.
Miryala R and Neilan R. N Engl J Med 2009;360:e32

15. Ingested magnets
A 9-year-old boy ingested 23 magnets (Panel A). Four days later, he had clinical and surgical evidence of intestinal perforation and peritonitis due to pressure necrosis of the bowel. In an unrelated incident, a developmentally delayed 13-year-old boy ingested 15 magnets. Ten days later, volvulus and intestinal occlusion developed (Panel B, arrows). Both patients were operated on without complications, and all magnets were removed. Although ingested nonmagnetic foreign bodies are likely to be passed spontaneously without consequence, ingested magnets may attract each other through the intestinal wall and cause severe damage, such as pressure necrosis, perforation, intestinal fistulas, volvulus, and obstruction. Thus, close observation and early intervention are warranted after ingestion of magnets.
Avolio L and Martucciello G. N Engl J Med 2009;360:2770

16. A 68-year-old man with chronic dysuria and increased urinary frequency presented with three weeks of weakness and fever
A 68-year-old man with chronic dysuria and increased urinary frequency presented with three weeks of weakness and fever. Physical examination revealed a man with cachexia who had a large, right-sided inguinal hernia that had been enlarging for more than eight years (Panel A). Computed tomography revealed unobstructed bowel within the hernia sac (Panel B, arrows). A urinary tract infection was diagnosed, and the patient received a course of levofloxacin. Given the size of the hernia, surgical repair would have involved multiple sequential procedures with a high risk of intraoperative death. The patient declined surgical intervention.
Rosmarin D and Tan C. N Engl J Med 2006;355:601

17. Radiographic Findings in Body Packers
Figure 2. Radiographic Findings in Body Packers. A plain abdominal radiograph shows multiple foreign bodies (Panel A). The "double-condom" sign (arrows) outlines many packets. Computed tomography of the abdomen demonstrates a single packet outlined by a rim of gas (Panel B, arrow).
Traub S et al. N Engl J Med 2003;349:

18. An 83-year-old woman was hospitalized with nausea, vomiting, and obstipation
An 83-year-old woman was hospitalized with nausea, vomiting, and obstipation. She had been losing weight for six months and had had similar, though less severe, symptoms during that time. She had no history of abdominal surgery and no other medical problems. The physical examination revealed a distended abdomen, with no palpable masses and no hernias. To distinguish an ileus from a mechanical small-bowel obstruction, enhanced computed tomography of the abdomen and pelvis was performed. Numerous distended loops of small intestine (Panel A, arrows), air in the biliary tree (Panel B, arrow), and a calcified intraluminal mass (Panel C, arrow) were identified. These findings established the diagnosis of gallstone ileus. The patient underwent a laparotomy with enterolithotomy, and the gallbladder was left in place. The patient had a full recovery.
Graham J and Rothwell B. N Engl J Med 2004;351:1119

19. A previously healthy 102-year-old woman was admitted with abdominal pain and a 3-day history of vomiting
A previously healthy 102-year-old woman was admitted with abdominal pain and a 3-day history of vomiting. She lived with relatives, but cared for herself, and was able to garden. There was no history of abdominal surgery. On examination, her abdomen was distended, she had pain in both hips, she could flex her knees, but no hernia was identifiable. Abdominal radiography revealed dilation of the small bowel (Panel A). Computed tomography showed an obturator hernia (arrow, Panel B). The hernia was surgically reduced, and an infarcted segment of the small bowel was resected. Postoperatively, despite complications of urinary sepsis and delirium, she recovered well. Twelve months later, she was still living at home, caring for herself, and able to sweep the floor at the age of 103 years.
Chan D. N Engl J Med 2006;355:1714

20. A 64-year-old woman with ulcerative colitis presented with abdominal pain
A 64-year-old woman with ulcerative colitis presented with abdominal pain. Plain radiography of the abdomen showed dilatation of the large bowel with a plug of barium (Panel A, arrow) and a second plug in the pelvis. The patient's last barium study, performed 9 months earlier, had been normal. Abdominal computed tomographic examination for strictures and underlying masses showed a short segment of thick-walled left colon immediately distal to the plug of barium in the abdomen (Panel B, arrow). The plug in the pelvis was found to be in the cecum and was not associated with small-bowel obstruction. The patient underwent a colonic wash under general anesthesia, followed by colonoscopic visualization of the inspissated barium, which was dissolved with a high-pressure jet stream of water. The large-bowel obstruction resolved, and colonoscopy a month later up to the terminal ileum showed no colonic strictures or residual barium plugs. Inspissation of barium can be minimized by keeping the patient well hydrated. If there is a history of constipation, patients should be encouraged to use a stool softener after a barium meal.
Kurer M and Chintapatla S. N Engl J Med 2007;356:1656

21. Take Home Points Always start with ABC, resuscitation DDX is simple:
Includes 2 large bore IV, Foley, NGT, monitor
DDX is simple:
SBO: Adhesions, Bulges, Cancer, Crohn’s
LBO: CANCER, Volvulus, Diverticulitis
Labs to assess dehydration & leukocytosis
Imaging to assess obstruction & etiology
If hypoTN/shock, “toxic”, or signs of strangulation or ischemia, resusc & OR stat
Otherwise, for SBO, NGT & treat etiology
LBO is different: really must rule out cancer, colonoscopy plays a larger role than w SBO