Editing Small bowel obstruction (section)

=== '''Specific situations:''' ===

* '''Complete SBO -''' monitor closely, generally needs OT
* '''Partial high-grade SBO (some gas in rectum) -''' initial observation, closely watched, may need theatre
* '''Partial low-grade SBO (bowels opening/passing flatus, but symptomatic on fluid intake) -''' can be safely watched in hospital
* '''SBO in virgin abdomen -''' Ask again about surgery, and check carefully for scars and hernias. Ask about history of trauma, and cancer that may have metastasised, and recent ingestion of bezoar-forming foods. According to one meta-analysis: 54% de novo adhesions, 11% malignancy, 2% internal hernia. The vast majority of patients will safely be managed non-operatively. It's worth thinking about outpatient workup for malignancy if non-op management is successful. This could be CT +/- MRI enteroclysis.
* '''SBO post-op -''' Mostly resolves with conservative management, consider TPN. >90% of early post-op obstructions are partial and will resolve spontaneously. However, need to be sure there are no signs of strangulation and no technical errors. Technical errors are more common after laparoscopic surgery, such as port site hernias.
* '''Recurrent SBO shortly after operation for same''' - initial non-op management. Very careful surgical technique. Many would advocate for prolonged non-op management and TPN until adhesions mature and the obstruction resolves. 
* '''Obstruction secondary to Crohn's -''' attempt conservative management with gut rest, TPN and steroids, involve medics, try to avoid OT. If have to operate, limited bowel resection or stricturoplasty.
* '''SBO with known intra-abdominal malignancy/potential recurrent malignancy -''' 30% have simple band adhesion, 30% need bowel resection, 30% inoperable - therefore probably deserve a laparotomy (aborting an operation may be better in many cases than not offering an operation that would have been simple). If they are already receiving palliative care input, and not far away from death, then less likely to offer an operation. 
* '''Malignant SBO (either primary or metastatic):''' median survival even with operation is 3-7 months, lower without (retrospective data), so a palliative procedure is not out of the question. Probably two types of patients - those with late cancer (do not operate), and those with first presentation of peritoneal disease (consider operating and debulking if good physiological reserve; think about patient's peritoneal carcinomatosis index (PCI)). Can sometimes offer bypass procedure.
* '''SBO secondary to abscess''' - percutaneous drainage may be sufficient, but laparotomy and washout may be the better option for large and established abscesses.
* '''SBO secondary to radiation enteropathy''' - follows a progressive course of gradually worsening partial obstructions, leading to a complete obstruction. Attempt to treat non-operatively, often with steroids. Can be a very difficult operation - paper-thin bowel, glued together and onto adjacent structures; accidental enterotomies are common and lead to fistulas. When longer segments are involved, bail out with an entero-enteric or entero-colic bypass. Poor prognosis no matter what you do.