eMedicine Specialties > Gastroenterology > Colon
Megacolon, Chronic: Treatment & Medication
Updated: Aug 3, 2007
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Treatment
Medical Care
- 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.
- Beyond these 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
- 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.
Consultations
These problems require a multidisciplinary approach, including the primary care provider, a gastroenterologist, a nutritionist/dietitian, and possibly a surgeon.
Diet
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.
Medication
A high water intake is an essential measure. A minimum of 6-8 8-oz glasses a day is recommended.
Bulking agents, through the increase of fiber, are also important. Many agents are on the market for this purpose and typically contain psyllium husk or cellulose; each patient may respond differently to each agent. No single agent is superior to another.
Laxatives may be considered and continued if found to be helpful. The best laxatives for this purpose are osmotic agents, such as magnesium salts, sorbitol, or lactulose (the latter two may increase flatulence). Patients need encouragement to take sufficient amounts to produce a result. Stimulant laxatives are best left as a last resort because they may possibly induce deterioration in the ability of the colon to evacuate. Typical stimulant laxatives are senna and bisacodyl-containing medications. Many patients take natural herbal laxatives; these typically contain cascara.
Tegaserod, a 5HT4 agonist, was approved for use in chronic constipation and in women with constipation-predominant irritable bowel syndrome. Its role in chronic pseudo-obstruction had not been determined.
Tegaserod marketing was temporarily withdrawn from the US market in March 2007; however, as of July 27, 2007, restricted use of tegaserod is now permitted via a treatment investigational new drug (IND) protocol. The treatment IND protocol will allow tegaserod treatment of irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC) in women younger than 55 years who meet specific guidelines. Its use is further restricted to those in critical need who have no known or preexisting heart disease.Earlier in 2007, tegaserod marketing was suspended because of a meta-analysis of safety data pooled from 29 clinical trials that involved more than 18,000 patients. The results showed an excess number of serious cardiovascular adverse events, including angina, myocardial infarction, and stroke, in those taking tegaserod compared with placebo. In each study, patients were assigned at random to either tegaserod or placebo. Tegaserod was taken by 11,614 patients, and placebo was taken by 7,031 patients. The average age of patients in these studies was 43 years, and most patients (ie, 88%) were women. Serious and life-threatening cardiovascular adverse effects occurred in 13 patients (0.1%) treated with tegaserod; among these, 4 patients had a heart attack (1 died), 6 had unstable angina, and 3 had a stroke. Among the patients taking placebo, only 1 (0.01%) had symptoms suggesting the beginning of a stroke that went away without complication.
For more information, see the FDA MedWatch Product Safety Alert.
Laxatives
Increase peristalsis of the intestine, reducing the time toxic substances remain in the lower GI tract.
Psyllium (Metamucil, Fiberall)
Promotes bowel evacuation by forming viscous liquid and perhaps by inducing peristalsis.
Adult
1-2 wafers, packets, or rounded teaspoonfuls qd/tid dissolved in 240 mL of liquid
Pediatric
<6 years: Not recommended
6-12 years: One half to 1 rounded teaspoonful qd/tid dissolved in 120 mL of liquid
>12 years: Administer as in adults
May decrease absorption and effects of salicylates, nitrofurantoin, tetracyclines, and diuretics
Documented hypersensitivity; fecal impaction, intestinal obstruction, or undiagnosed abdominal pain
Pregnancy
B - Usually safe but benefits must outweigh the risks.
Precautions
Caution in intestinal adhesions, ulcers, or intestinal stenosis
Magnesium hydroxide (Philips' Milk of Magnesia)
Causes osmotic retention of fluid, which distends the colon and probably increases peristaltic activity; promotes emptying of bowel.
Adult
5-15 mL or 650 mg to 1.3 g tabs PO; not to exceed qid prn
Pediatric
2.5-5 mL PO; not to exceed qid prn
Decreases effects of tetracyclines, digoxin, indomethacin, and iron salts
Documented hypersensitivity; colostomy, ileostomy, renal failure, fecal impaction, and appendicitis
Pregnancy
B - Usually safe but benefits must outweigh the risks.
Precautions
Caution in severe renal impairment
Sorbitol
Hyperosmotic laxative that has cathartic actions in the GI tract.
Adult
30-150 mL PO of a 70% solution
Pediatric
<2 years: Not recommended
2-11 years: 2 mL/kg PO of 70% solution
>12 years: Administer as in adults
Reduces effectiveness of other drugs when administered concomitantly
Documented hypersensitivity; anuria
Pregnancy
C - Safety for use during pregnancy has not been established.
Precautions
Caution in severe cardiopulmonary or renal impairment and in patients who cannot metabolize sorbitol
Lactulose (Cephulac, Cholac, Constilac)
Produces osmotic effect in colon that results in distention and promotes peristalsis.
Adult
20-30 g (30-45 mL) PO q1-2h; slowly adjust dose to produce 2-3 soft stools
Pediatric
5 g/d (7.5 mL) after breakfast
Decreases effects of neomycin, laxatives, and antacids
Documented hypersensitivity; patients who require a galactose diet
Pregnancy
B - Usually safe but benefits must outweigh the risks.
Precautions
Caution in diabetes mellitus and monitor for electrolyte imbalance
Senna (Senexon, Ex-Lax, Senokot, Senna-Gen, Black-Draught, Agoral)
Anthraquinone stimulant hydrolyzed by colonic bacteria into active compound. More potent than cascara sagrada and produces considerably more abdominal pain. Usually produces action 8-12 h after administration.
Adult
0.12-0.25 g PO qd
Pediatric
<6 years: Not recommended
>6 years: Administer as in adults
Decreases effects of anticoagulants
Documented hypersensitivity; nausea, vomiting, GI bleeding, appendicitis, congestive heart failure, fecal impaction, appendicitis
Pregnancy
B - Usually safe but benefits must outweigh the risks.
Precautions
Excessive use may lead to electrolyte imbalance, osteomalacia, steatorrhea, cathartic colon
Bisacodyl (Bisac-Evac, Bisco-Lax, Dulcolax, Dacodyl)
Stimulates peristalsis, possibly by stimulating colonic intramural plexus. Alters water and electrolyte secretion, producing net intestinal fluid accumulation and laxation.
Adult
5-15 mg PO as single dose
10 mg PR as single dose
Pediatric
5-10 mg (0.3 mg/kg) PO/PR hs or before breakfast
Decreases effects of warfarin and antacids
Documented hypersensitivity; abdominal pain, nausea or vomiting, GI obstruction
Pregnancy
C - Safety for use during pregnancy has not been established.
Precautions
Caution in ulceration of colon and during pregnancy or lactation
Cascara sagrada
Irritates intestinal mucosa, increasing rate of colonic motility and changes fluid and electrolyte secretion.
Adult
5-6 mL or 1 tab PO hs
Pediatric
Infants: 0.5-1.5 PO mL/d prn
2-11 years: 1-3 PO mL/d prn
Decreases effects of anticoagulants
Documented hypersensitivity; nausea, vomiting, GI bleeding, appendicitis, congestive heart failure, fecal impaction, appendicitis
Pregnancy
B - Usually safe but benefits must outweigh the risks.
Precautions
Excessive use may lead to electrolyte imbalance, osteomalacia, steatorrhea, cathartic colon
Polyethylene glycol (PEG) solution
For treatment of occasional constipation. In theory, less risk of dehydration or electrolyte imbalance with isotonic polyethylene glycol compared with hypertonic sugar solutions. Laxative effect generated because polyethylene glycol is not absorbed and continues to hold water by osmotic action through small bowel and colon, resulting in mechanical cleansing. In theory, less risk of dehydration or electrolyte imbalance with isotonic polyethylene glycol compared with hypertonic sugar solutions. The laxative effect is generated because polyethylene glycol is not absorbed and continues to hold water by osmotic action through the small bowel and the colon, resulting in mechanical cleansing. Supplied with measuring cap marked to contain 17 g of laxative powder when filled to the indicated line. May require 2-4 d (48-96 h) to produce bowel movement.
Adult
Dissolve 17 g in 8 oz of water and drink daily prn for up to 2 wk
Pediatric
Not established
May decrease oral medication absorption, thereby decreasing effectiveness
Documented hypersensitivity; colitis, ileus, megacolon, bowel perforation, gastric retention, or GI obstruction
Pregnancy
C - Safety for use during pregnancy has not been established
Precautions
Caution in ulcerative colitis or hot loop polypectomy; not for use >2 wk
More on Megacolon, Chronic |
| Overview: Megacolon, Chronic |
| Differential Diagnoses & Workup: Megacolon, Chronic |
Treatment & Medication: Megacolon, Chronic |
| Follow-up: Megacolon, Chronic |
| References |
| « Previous Page | Next Page » |
References
Barnes PR, Lennard-Jones JE, Hawley PR, Todd IP. Hirschsprung's disease and idiopathic megacolon in adults and adolescents. Gut. May 1986;27(5):534-41. [Medline].
Camilleri M. Acute and chronic pseudo-obstruction. In: Felman M, Friedman LS, Sleisenger MH, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 8th ed. Philadelphia: Saunders; 2007:2679-2702.
Camilleri M. Dysmotility of the small intestine and colon. In: Yamada T, ed. Textbook of Gastroenterology. Vol 1. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2003:1486-1529.
Harari D, Minaker KL. Megacolon in patients with chronic spinal cord injury. Spinal Cord. Jun 2000;38(6):331-9. [Medline].
Krishnamurthy S, Heng Y, Schuffler MD. Chronic intestinal pseudo-obstruction in infants and children caused by diverse abnormalities of the myenteric plexus. Gastroenterology. May 1993;104(5):1398-408. [Medline].
Lane RH, Todd IP. Idiopathic megacolon: a review of 42 cases. Br J Surg. May 1977;64(5):307-10. [Medline].
Metcalf AM, Phillips SF, Zinsmeister AR, MacCarty RL, Beart RW, Wolff BG. Simplified assessment of segmental colonic transit. Gastroenterology. Jan 1987;92(1):40-7. [Medline].
Miyamoto M, Egami K, Maeda S, Ohkawa K, Tanaka N, Uchida E, et al. Hirschsprung's disease in adults: report of a case and review of the literature. J Nippon Med Sch. Apr 2005;72(2):113-20. [Medline].
Nicholls RJ, Kamm MA. Proctocolectomy with restorative ileoanal reservoir for severe idiopathic constipation. Report of two cases. Dis Colon Rectum. Dec 1988;31(12):968-9. [Medline].
Porter NH. Megacolon: A physiological study. Proc R Soc Med. 1961;54:1043.
Preston DM, Lennard-Jones JE, Thomas BM. Towards a radiologic definition of idiopathic megacolon. Gastrointest Radiol. 1985;10(2):167-9. [Medline].
Stabile G, Kamm MA, Hawley PR, Lennard-Jones JE. Colectomy for idiopathic megarectum and megacolon. Gut. Dec 1991;32(12):1538-40. [Medline].
Stryker SJ, Pemberton JH, Zinsmeister AR. Long-term results of ileostomy in older patients. Dis Colon Rectum. Nov 1985;28(11):844-6. [Medline].
Further Reading
Keywords
Ogilvie syndrome, pseudo-obstruction, idiopathic megacolon, acquired megacolon, toxic megacolon, colonic inertia, generalized delayed transit, rectosphincteric dyssynergy, functional outlet obstruction, spontaneous perforation, Hirschsprung disease, megarectum, Trypanosoma cruzi, T cruzi, Chagas disease, unrecognized imperforate anus, total abdominal colectomy with ileorectal anastomosis, total proctocolectomy with ileostomy, total proctocolectomy with ileoanal anastomosis
Treatment & Medication: Megacolon, Chronic