When consulting your surgical colleagues about a potential small bowel obstruction, you may often be requested to place a nasogastric tube for bowel decompression regardless of how the patient appears clinically. Your patient will almost certainly dislike the procedure (prior studies have suggested patients find NGT placement to be the MOST painful ED procedure, over I&Ds and fracture reduction). And if they are not actively vomiting, your patient may also not really benefit from the procedure. A 2013 retrospective chart review in The American Surgeon found no better outcomes (and in fact worse outcomes: longer lengths of stay + longer time to resolution + higher respiratory complications) among conservatively-managed non-vomiting patients with SBO. The study certainly is effected by some selection bias, but still lends credibility to the already present ED skepticism regarding empiric NGT placement in all potentially obstructed patients.
Fonseca A, Schuster K, et al. Routine Nasogastric Decompression in Small Bowel Obstruction: Is It Really Necessary? The American Surgeon, Volume 79, Number 4, April 2013, pp. 422-428(7)
Singer AJ, Richman PB, Kowalska A, Thode HC Jr. Comparison of patient and practitioner assessments of pain from commonly performed emergency department procedures. Ann Emerg Med. 1999; 33(6): 652-8. PMID: 10339680