Managing patients with chronic megacolon requires a multidisciplinary approach, including the primary care provider, a gastroenterologist, a nutritionist/dietitian, and possibly a surgeon.
In the absence of perforation, initial management is conservative. Some experts believe a role exists for as-needed fecal disimpaction and for evacuation by enemas and suppositories.
Pay close attention to exclusion of any underlying cause. If identified, correct electrolyte/metabolite abnormalities, and remove medications that may influence colonic motility (eg, narcotics, anticholinergic agents, calcium channel antagonists).
The use of biofeedback for a colonic inertia etiology for chronic megacolon is probably not effective, although successful treatment of functional outlet obstruction with biofeedback has been reported.
In patients requiring hospitalization, decompression using nasogastric tubes and rectal tubes may assist in treatment. When such tubes are used, anecdotal experience has demonstrated that frequent position changes for the patient may help to improve decompression.
If the dilatation persists or worsens, colonoscopic decompression can be attempted, with consideration of placement of a decompression tube, per rectum, to the right side of the colon. Unfortunately, following decompression, the dilatation usually recurs; therefore, decompression with colonoscopy must be carefully considered, as it is not without risk in an unprepared, dilated colon. Many gastroenterologists no longer consider placement of a drainage tube at the time of colonoscopy, as it nearly always becomes clogged with stool and rapidly ceases to function.
Maintenance of a strict bowel habit retraining program is important. Therefore, beyond the above options for the treatment of acute megacolon, the recommended regimen for chronic megacolon in a stable patient is as follows:
Empty the bowel (eg, osmotic laxatives, enemas, suppositories, cathartics, digital disimpaction).
Practice a bowel habit retraining program (eg, scheduled times for defecation, increased physical activity if possible).
Consume bulking agents/bowel agents.
Slowly alter/individualize the regimen.
Surgical care is generally recommended if the dilatation is persisting or worsening after the above medical measures have been exhausted.
Megacolon operative options include total abdominal colectomy with ileorectal anastomosis, total proctocolectomy with ileostomy, and total proctocolectomy with ileoanal anastomosis, depending on the site of the colon affected.
Total abdominal colectomy with ileorectal anastomosis is the operation of choice of megacolon with normal-sized rectum.
Patients with acquired, nonacute megacolon should follow a high-fiber, high-fluid intake diet, which usually helps to decrease constipation. Some patients with severe constipation state that a high-fiber diet produces greater difficulty with bloating and constipation.