'''Passage of a stomach tube''' will produce nasogastric reflux depending on the site of obstruction and its duration; for a proximal obstruction fluid will build up in the stomach after approximately 3-6 hours, and for a distal obstruction, after 12 hours. | '''Passage of a stomach tube''' will produce nasogastric reflux depending on the site of obstruction and its duration; for a proximal obstruction fluid will build up in the stomach after approximately 3-6 hours, and for a distal obstruction, after 12 hours. |