The management of a patient with colonic obstruction or pseudo-obstruction is shown in Fig. 23.1. The first step is to rule out mechanical obstruction and treat any underlying medical conditions that may predispose to dysmotility. An abdominal radiograph will typically reveal dilated colon loops and allow for assessment of the degree of distention and aid in localizing the site of obstruction.³ Fig. 23.2 shows distended colonic loops and increased stool burden in a patient with acute sigmoid volvulus. Abdominal computed tomography (CT) provides more detailed imaging that aids in evaluation of the etiology of obstruction. A conservative management approach is typically pursued in the absence of signs of peritonitis or impending perforation. This includes nothing by mouth, nasogastric tube placement, body positioning (knee-chest position or prone position with hip held high), intravenous hydration and correction of electrolyte
abnormalities, enemas, and rectal tube placement. This is typically pursued for a period of 24 to 48 hours with close clinical monitoring. If these measures fail and obstruction is excluded radiologically, pharmacologic measures to treat pseudo-obstruction may be considered. Neostigmine is the most commonly used agent,⁴ while metoclopramide, erythromycin, and cisapride (not available in the United States) are used less commonly. The risk of complications increase with increasing diameters of the colon⁵ (more than 9 cm for the transverse colon and 12 cm for the cecum), although this also depends on the acuity and rate of progression of the increase in colon diameter.