Overview

Some people require a total or partial removal of their colon and rectum if they are diseased and damaged. One method of replacing the rectum is to reconstruct a pouch out of the ileal end of the small intestine and attach it (anastomosed) to the anus. This ileal pouch can become inflamed and infected, known as pouchitis.

What is the function of the lower digestive system?

The digestive system involves a network of various organs from the mouth to the anus. The food you eat passes through this system during digestion. Pouchitis is a condition that affects the lower end of the digestive tract. The lower digestive tract is made up of the small intestine, large intestine (colon), rectum and anus. Their overall functions are to digest food, absorb nutrients and water, and store and excrete waste.

What are the common reasons for colorectal surgery?

As with any of the body's organs, things can go wrong. Some diseases affect the structure and functioning of the lower digestive tract. If the colon and rectum are damaged then it may be necessary to surgically remove them. The most common reasons for colorectal surgery are:

Ulcerative colitis

This is a form of inflammatory bowel disease. It causes inflammation and ulceration of the large intestine and rectum. In ulcerative colitis, the immune system accidentally attacks the intestine causing this damage. Symptoms of ulcerative colitis generally come and go and are known as flare-ups. After living with ulcerative colitis for a long time the intestine may have become damaged. Up to 25% of patients with ulcerative colitis require surgery and most of these have an ileoanal pouch.¹

Colorectal cancer

Colorectal cancer is one of the most common cancers. In this cancer, tumour masses grow from the colon or rectum wall. It is often necessary to surgically remove the tumours and the surrounding tissue to prevent them from growing further or spreading to other areas of the body.

Familial adenomatous polyposis (FAP)

FAP is a rare genetically inherited condition that predisposes people to have multiple growths (polyps) throughout the colon. This is a problem because people with this condition have a very high likelihood of developing colorectal cancer. It is therefore often necessary to remove the entire colon and rectum to reduce a person’s risk of getting colorectal cancer in the future.

Diverticulitis

Diverticulitis is an inflammation of a diverticula (a small pocket inside the colon). Some people with long-term diverticulitis may require the removal of their colon if their condition has caused significant colon damage. 

Traumatic injury

Some people might have a traumatic injury to the colon such as from a car accident. It may be necessary to remove part of the colon if it is no longer functional or if it is dead and there is a risk of infection

What are the different types of colorectal surgery (proctocolectomy)?

When the intestine is diseased or damaged beyond repair, it is often necessary to remove parts of it. The amount of the intestine that needs to be removed will depend on the extent and severity of the damage. In some cases, a complete removal of all the colon and rectum is required, this is known as a total proctocolectomy. It may only be necessary to remove part of the colon or rectum, this is known as a subtotal proctocolectomy.

If the rectum has been removed it is no longer possible for the body to control the passage of waste. A surgeon can make a pouch out of the end of the small intestine (ileum) which can function like a rectum to store poo. The pouch can then be attached in what is known as an anastomosis to the anus so that waste can be excreted. This pouch is known as an ileal pouch-anal anastomosis (IPAA).² The main benefit of the ileal pouch is that the patient no longer needs an external bag, which has a lot of associated issues. The most common type of pouch is a J-pouch.

In some cases, it isn’t possible to connect the small intestine and the anus back together and the surgeon must make a hole in your abdomen through which the small intestine can be emptied. If it is the ileal end of the small intestine which empties into the bag, it is known as an ileostomy, if it is the colon it is a colonostomy. These external ‘ostomies’ can be temporary to allow the newly formed internal pouch time to heal or they can be permanent.

What is pouchitis?

There are several different complications that can arise with internal ileal pouches but pouchitis is the most common. This is an inflammation of the ileal pouch and it occurs in up to 50% of people who have ileal pouch surgery.²

What causes pouchitis?

Several different factors are thought to contribute to the development of pouchitis. One of the problems with using the small intestine to create an artificial pouch is that it is not designed for this function. This can result in the digestive waste collecting abnormally (faecal stasis) which can cause inflammation.³

As the ileal pouch is attached to the anus, it is now exposed to different bacteria than it is used to. This can trigger an inflammatory response from the immune system. Pouchitis is thought to be caused by a disruption of the balance of different bacteria (dysbiosis) and the domination of more dangerous bacteria, leading to infections.⁴

There are some genetic mutations associated with developing pouchitis and increased disease severity.⁴ It has also been found that the interruption and reperfusion of the blood supply to the intestine could be responsible for the development of pouchitis.⁴

What are the main symptoms of pouchitis?

The following are symptoms commonly associated with pouchitis:²

• Pain or cramping in the lower abdomen
• Needing to poo urgently or more frequently
• Bowel incontinence
• Straining when you poo
• Blood in your poo
• Fever

Symptoms can be acute (≤ 4 weeks) or chronic (≥ 4 weeks).² They often come in episodes. Symptoms can recur frequently or infrequently. In some people, symptoms recur and become a long-lasting (chronic) problem. Please consult your local doctor if you are concerned about your symptoms.

How is pouchitis diagnosed?

A doctor will review your symptoms to make a diagnosis. Conditions with similar symptoms would need to be excluded:

• Cuffitis (inflammation of the rectal cuff)
• Crohn’s disease of the pouch⁴
• Clostridium difficile or cytomegalovirus (CMV) infections⁵

A doctor will perform a medical examination to look for signs of the disease. They will ask you questions about your past medical and surgical histories. If pouchitis is suspected, they may examine the pouch using an endoscope (a camera on a tube inserted into your bottom). This particular endoscopic examination is referred to as pouchoscopy.⁶ Tissue samples (biopsy) may also be taken for further investigations. The pouchitis disease activity index (PDAI) score is one way doctors diagnose pouchitis, based on symptoms, examination, and pouchoscopy findings.²

What are the risk factors for pouchitis?

The following have been found to increase the risk of developing pouchitis:⁴

• Long-term non-steroidal anti-inflammatory drug (NSAID) use
• Extensive ulcerative colitis
• Extraintestinal features of inflammatory bowel disease (e.g., joint, eye and skin diseases)
• Primary Sclerosing Cholangitis (PSC)
• Age (younger patients are more likely to develop pouchitis)

What is the treatment for pouchitis?

Antibiotics

A 2-4 week course of antibiotics is the first line of treatment. If this doesn’t work the doctor might try different antibiotics or you may be required to undergo a longer treatment course.³ If you still have symptoms for more than 4 weeks, your pouchitis is termed chronic antibiotic-dependent pouchitis (CADP) or chronic antibiotic-resistant pouchitis (CARP).³

Probiotics

Some probiotics have been found to be effective at reducing the development of pouchitis following ileal pouch-anal anastomosis surgery.⁷

What are the complications associated with pouchitis?

When pouchitis is long-term (chronic) it can cause other complications:

• Can make bowel movements more difficult (i.e., increased constipation or diarrhoea)
• Malabsorption of nutrients
• Pouch scarring, ulceration, or bleeding
• Negatively affects your quality of life
• Pouch failure and the need for an external ostomy bag

Summary

Some people require surgery to remove their damaged and diseased colon and rectum (proctocolectomy). The most common diseases requiring this surgery are ulcerative colitis, colorectal cancer, familial adenomatous polyposis, diverticulitis, and traumatic injury to the colon. In order to replace the rectum, an internal ileal pouch is constructed from the end (ileum) of the small intestine. The main complication of this surgery is that the pouch becomes inflamed (pouchitis). Pouchitis is caused by an imbalance of the bacteria in the pouch and it presents with symptoms of abdominal pain, urgency, blood in your poo, and fever. The symptoms can be acute or chronic and often come in episodes. Pouchitis is diagnosed based on symptoms, examination and imaging. There are some risk factors such as long-term use of NSAIDs, having extensive ulcerative colitis, having extraintestinal manifestations of inflammatory bowel disease, and being young. Treatment will be determined by your doctor but usually consists of 2-4 weeks of antibiotics. Certain probiotic formulations have also been found to be effective for some people. Long-term pouchitis can cause complications such as making bowel motions more difficult, malabsorption of nutrients, pouch scarring, ulceration and bleeding, and overall reduced quality of life. If the pouch is unsuccessful then an external pouch (ostomy bag) may be required. Please consult your local doctor if you are concerned about your symptoms.