Bowel/intestinal obstruction is mechanical/functional obstruction of the intestine, preventing normal transit of feces.

SBO is shorthand for Small bowel obstruction.

• Sx depends on the level of obstruction
• Abdominal pain, which tends to be:
  • In small bowel obstruction:
    • Colicky (cramping and intermittent) in nature, w/ spasms lasting a few minutes
    • Pain tends to be central and mid-abdominal
  • In large bowel obstruction:
    • Pain felt lower in the abdomen, w/ spasms lasting longer
    • Constipation occurs earlier
    • Proximal obstruction of the large bowel may present as small bowel obstruction
• Swollen abdomen
• Abdominal distension
• Vomiting, including fecal vomiting
  • In small bowel obstruction, vomiting may occur before constipation
  • In large bowel obstruction, vomiting may be less prominent
• Constipation, absence of normal stool/flatus
• Increased bowel sounds

• Can occur at any level distal to the duodenum (of the small intestine)

• Small intestine obstruction, including:
  • Adhesions from previous abdominal surgery, most commonly
  • Pseudoobstruction
  • hernias containing bowel
  • Crohn's disease, causing adhesions or inflammatory strictures
  • Neoplasms, benign or malignant
  • Intussusception in children
  • Volvulus
  • Superior mesenteric artery syndrome, a compression of the duodenum by the superior mesenteric artery and abdominal aorta
  • Ischemic strictures
  • Foreign bodies, e.g. gallstones in gallstone ileus, swallowed objects
  • Intestinal atresia
• Large intestine obstruction, including:
  • Neoplasms
  • Diverticulitis/diverticulosis
  • Hernias
  • Inflammatory bowel disease
  • Colonic volvulus (sigmoid, cecal, transverse colon)
  • Adhesions
  • Constipation
  • Fecal impaction
  • Fecaloma
  • Colon atresia
  • Intestinal pseudoobstruction
  • Endometriosis
  • Narcotic induced, especially w/ the large doses given to cancer or palliative care Pt's

• Blood tests
• Imaging, including:
  • Abdo x-ray, which may show bowel distension, and presence of multiple (>6) gas fluid levels on supine and erect abdominal radiographs. The appearance of water-soluble contrast in the cecum on abdo x-ray w/in 24 hours of oral administration predicts resolution of an adhesive small bowel obstruction

Source: Slideshare CDN

• • Luminal contrast studies, including contrast enema, small bowel series, or CT, can define the level of obstruction, whether the obstruction is partial or complete, and define the cause of obstruction
  • U/S
• Biopsy, to determine the nature of the mass, if a mass is identified
• Colonoscopy, small bowel investigation w/ ingested camera or push endoscopy, and laparoscopy

• Ileus
• Pseudo-obstruction or Ogilvie's syndrome
• Intra-abdominal sepsis
• Pneumonia, or other systemic illness

• Mostly Tx conservatively over 2-5 days (e.g. in Crohn's disease, peritoneal carcinomatosis, sclerosing peritonitis, radiation enteritis, and postpartum bowel obstruction), because in many cases, the bowel will open up. Some adhesions loosen up, and the obstruction resolves. However, this requires close monitoring, examined several times a day, and x-rays taken to ensure the Pt is not clinically getting worse. It includes:
  • Insertion of an NG tube, to correct dehydration and electrolyte abnormalities
  • Opioid pain drugs, can be used for Pt's w/ severe pain
  • Antiemetics, if the Pt is vomiting
• Surgical intervention to Tx the causative lesion, in surgical emergencies (e.g. volvulus, closed-loop obstructions, ischemic bowel, incarcerated hernias, fully lodged foreign object, malignant tumor), including bowel resection or lysis of adhesions
• Endoscopically placed self-expanding metal stents, may be used to temproarily relieve the obstruction as a bridge to surgery, or as palliation, in malignant large bowel obstruction
• NG tube inserted from the nose into the stomach, to help decompress the dilated bowel. The tube is uncomfortable but does relieve the abdominal cramps, distension and vomiting
• IV therapy
• Catheter in the bladder, to monitor urine output

• Dehydration
• Electrolyte abnormalities, due to vomting
• Respiratory compromise, from pressure on the diaphragm by a distended abdomen, or aspiration of vomitus
• Bowel ischemia or perforation from prolonged distension or pressure from a foreign body

• It is a medical emergency
• Some causes of bowel obstruction may resolve spontaneously
• 6% of small bowel obstruction, are ultimately fatal if Tx is delayed

• Abdominal examination