How can small bowel obstruction cause inability to pass gas but not inability to pass stool?
The stool distal to the obstruction may still pass (along with the gas), but that proximal to the obstruction is stuck, giving the classic finding of small-bowel gas (keeping in mind that you normally see no, or almost no, gas in the small bowel). What’s actually happening is that the small bowel gas is backing up and the stool you see coming out is only that which already was distal to the obstruction, so appearances don’t exactly correlate with the internal reality..
