The ileoanal pouch ("pull-through") and the continent ileostomy (Kock pouch) are alternatives to the standard ileostomy. Both eliminate the need to wear an external ostomy appliance. In each case, the surgeon uses part of the patient's small intestine to create an internal pouch for the storage of stool. Sometimes the mucosa, or lining, of this internal pouch becomes inflamed. This complication is known as "pouchitis."

What are the symptoms of pouchitis?

For people who have undergone ileoanal pouch surgery, the main symptom is an abnormally large number of stools: an increase from three-four per day to five-six (on average), or more; or very frequent stools (eight or more per day). These patients also may experience rectal bleeding, abdominal cramping, a sense of "urgency" before having a bowel movement, and fever. In addition to suffering from cramping and fever, people who have undergone Kock pouch surgery may find that the ileostomy effluent is more watery, and that they need to intubate the pouch more frequently. Occasionally, there may be blood in the effluent.

How is pouchitis diagnosed?

Patients who have any of the symptoms listed above could have pouchitis. But several other conditions also could cause similar symptoms. These include irritable bowel syndrome, small-bowel obstruction from scar tissue, narrowing of the connection (anastomosis) between the anus and the pouch (in the case of people who have undergone ileoanal pouch surgery), an intestinal infection with bacteria or parasites, and Crohn's disease. For this reason, patients whose symptoms suggest pouchitis should have a flexible sigmoidoscopy (examination of the pouch with a flexible lighted instrument). At this time, biopsies (tissue samples) of the pouch also should be obtained. In patients with pouchitis, flexible sigmoidoscopy will reveal inflammation, similar to that found in ulcerative colitis, in the mucosa of the pouch. When examined under the microscope, the biopsies also will show inflammation. If inflammation is not present, then other causes for the patient's symptoms should be considered.

How often does pouchitis occur?

32% of all patients with an ileoanal pouch have had at least one episode of pouchitis. This figure comprises all patients who have had the pouch for anywhere from one year to 14 years. The longer the time since the pouch was created, the more likely it is that pouchitis will occur: 15% of patients will experience pouchitis at one year; 36% at five years; and 46% at 10 years. (Note: While these statistics, like those quoted later in this article, apply specifically to ileoanal pouch surgery, they are roughly the same for patients who have Kock pouches.)

What causes pouchitis?

The cause of pouchitis is not known, just as we do not know the cause of ulcerative colitis and Crohn's disease. Researchers have suggested several theories: an excess of bacteria in the pouch; a recurrence of inflammatory bowel disease (IBD) in the pouch; and misdiagnosis of ulcerative colitis, before surgery, in a patient who really has Crohn's disease.

People who suffer from pouchitis often improve with antibiotics, which suggests that bacteria are an important factor in the development of this condition. Pouchitis occurs more commonly in people with extraintestinal problems associated with ulcerative colitis (e.g., arthritis or abnormalities of the liver, skin, or eyes). These findings suggest that pouchitis may be a new type of IBD, which recurs in the pouch. Most patients with pouchitis do not have Crohn's disease. Indeed, misdiagnosis of Crohn's disease as ulcerative colitis in patients undergoing iloeanal pouch surgery is uncommon.

Research is being done to identify the cause of pouchitis. Some investigators are looking for "triggering" bacteria or disease markers, such as antibodies. One early finding is that pouchitis is more common in ulcerative colitis patients who have antineutrophil cytoplasmic antibodies (ANCA) in their blood. But, while people with ANCA may be more susceptible to pouchitis, this does not mean that every patient who has undergone ileoanal pouch or Kock pouch surgery and who has ANCA will get pouchitis. The most likely cause is twofold: a genetic susceptibility to both ulcerative colitis and pouchitis, combined with a "trigger," such as bacteria, within the stool in the pouch.

How is pouchitis treated?

Antibiotics are the most common treatment for pouchitis. The most commonly used antibiotic is metronidazole (Flagyl®). Most, if not all, patients initially improve after taking metronidazole, usually within one or two days. The length of treatment is usually one-two weeks. Patients with frequent flare-ups of pouchitis may require continual treatment.

Other antibiotics that are sometimes prescribed include ciprofloxacin, amoxicillin/clavulanic acid (Augmentin®), erythromycin, and tetracycline. Drugs used to treat ulcerative colitis are also sometimes used in pouchitis. These include steroid enemas (e.g., Cortenema®); 5-aminosalicylate enemas or suppositories (e.g., Rowasa®); sulfasalazine; and oral 5-aminosalicylate compounds (e.g., Asacol® and Pentasa®). In very rare cases, oral steroids (e.g., prednisone) may be prescribed, but their use in pouchitis is much less frequent than in ulcerative colitis.

What happens to patients with pouchitis?

Out of 100 patients with the ileoanal pouch, 68 will never get pouchitis. Of the 32 persons who do develop this condition, 12 will have a single episode that improves with a short course of treatment (one-two weeks) with antibiotics, and they will never get pouchitis again. For these patients, having a single episode of pouchitis is not much different from having a urinary infection or the flu. Fifteen patients will have recurrent flare-ups, which will occur anywhere from once a year to once every three months. This pattern is a nuisance and, in some respects, is like having ulcerative colitis again. The majority of these patients, however, are easily treated with antibiotics or other safe medications, such as 5-aminosalicylate enemas or suppositories, sulfasalazine, or oral 5-aminosalicylate compounds. Though not ideal, this is better than the original ulcerative colitis, which often required treatment with oral steroids and which carried the risk of colon cancer. Chronic symptoms of pouchitis will occur in five out of 100 persons. These patients often do not respond to treatment. For this small group, pouchitis has a major negative impact on the quality of life, and they may choose to have the pouch converted to a permanent ileostomy.

Should concerns about getting pouchitis discourage me from having ileoanal pouch surgery?

Based on the most recent information available, the answer is no. Most patients with the ileoanal pouch or the Kock pouch never get pouchitis. Even people who do develop pouchitis find that their quality of life is better than when they had ulcerative colitis, and better than it would be with an ileostomy. Only a small number of patients suffer from chronic pouchitis. In virtually all cases, the problem can be eliminated by converting to a standard ileostomy.

--William J. Sandborn, M.D. IBD Clinic Mayo Clinic, Rochester, MN