Acute Megacolon Workup
- Author: Roberto M Gamarra, MD; Chief Editor: BS Anand, MD more...
Laboratory studies are directed at establishing the etiology of the acute megacolon as well as determining the patient's fluid status, and they include the following.
- Complete blood count
- Electrolytes (including calcium, magnesium, and phosphorus)
- BUN and creatinine
- Thyroid studies
- Stool studies (including leukocytes, ova and parasites, and C difficile toxin assay)
- Blood cultures
Imaging studies are used to determine severity, to exclude free intraperitoneal air (perforation) as well as other etiologies (eg, extrinsic compression), and to follow clinical course.
Plain x-ray films of the abdomen demonstrate the massive gaseous distention of the colon. Generally, the small bowel is not seen. Dilation of all segments of the colon support the diagnosis of pseudo-obstruction.
Other imaging studies, such as hypaque enema, CT scanning, or MRI, may also be used to exclude obstruction.
Perform other tests only to rule out a mechanical obstruction. Depending on the setting, severity, and condition of the patient, these tests may include either a colonoscopic examination (which also may be therapeutic) or a water-soluble contrast enema. Colonoscopy is preferred because of its diagnostic and therapeutic potential.
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