Complications of Crohn’s Disease

Aphthous Ulceration

Aphthous Ulcers are small, white, superficial lesions with a reddened margin. They are usually around 0.5 cm in diameter. They can be single or multiple and can occur anywhere within the mouth.

What is the cause?

They usually occur with disease flare-ups in inflammatory bowel disease and tend to be more common in Crohn’s disease (CD) (around 6-20%).

What is the treatment?

As most ulcers occur during flare-ups, controlling the disease may provide relief.
Topical preparations may be helpful such as:

  • antibiotic suspensions.
  • steroid ointments.
  • antacid suspensions.
  • local anaesthetic solutions or gels if the ulcers are painful.

Ankylosing Spondylitis

Ankylosing Spondylitis is a rheumatic disease mainly affecting the spine and particularly the joint between the hip bone and the spine – a condition called sacro-ileitis

How does it occur?

Following periods of inflammation, as healing occurs, bone grows out from both sides of the vertebrae (bones of the spine), and may join them together causing stiffness and immobility (bamboo spine).

What is the cause?

The cause is unknown but there are certain factors, which may predispose to the condition:

  1. There is an increased incidence of ankylosing spondylitis in Inflammatory Bowel Disease (IBD) (around 10 – 20 times more common than would be seen in the general population).
  2. If a first-degree relative has IBD, the chances of ankylosing spondylitis are increased.
  3. There is a genetic tendency. Around 90% of patients with ankylosing spondylitis have the white cell group HLA-B27. However, many other members of the general population (including siblings of sufferers) also having this blood group, never develop the disease.

What are the symptoms?

Ankylosing spondylitis is a progressive disease; i.e. it starts off with maybe only minimal effects, which gradually get worse over the course of time. Early signs may show:

  • low backache and stiffness
  • aches and pains in the neck, shoulder and hip
  • sciatica-type pain felt down the thigh

These may be mild and intermittent causing few troubles, or more active causing weight loss, fatigue and a general feeling of being unwell. Other joints such as the hip, knee and ankle may be affected causing similar problems to those of the spine.

How do I know that I have the condition?

Backache may be present for several years. Tests, which eventually may lead to a diagnosis, include:

  1. A blood test: The erythrocyte sedimentation rate (ESR) will be raised indicating inflammation.
  2. X-rays: X-rays of the sacro-iliac joints and spine.
  3. HLA-B27 antigen test: This is similar to blood grouping, but is looking at the white cells. If positive, this may indicate susceptibility to the disease.

What is the treatment?

Treatment generally involves pain relief and keeping fit and healthy.
The disease is slowly progressive, but symptomatic relief is achievable and a full life can usually be enjoyed.


It is important to maintain as good a posture as possible, keeping the back straight at all times.

  • Avoid stooping over a desk at work.
  • Avoid sitting in one position for too long without moving the back.
  • Corsets and braces may make the condition worse as muscles that support the back may become weak due to immobility.
  • A firm bed may provide more comfort in keeping the spine straight. Consider using a board under the mattress if necessary.

Sport and exercise

Keeping active is helpful. Swimming, in particular, allows good use of all muscles and joints without injury.


Research has suggested that diet may have an effect on the treatment of ankylosing spondylitis. The organism Klebsiella has been isolated in stools of patients with active disease and improvements have been claimed in some patients by following a low carbohydrate diet. These patients have also been found to be HLA-B27 positive. This treatment, however, has yet to achieve general acceptance by rheumatologists.
Most cases of ankylosing spondylitis will gradually burn out and patients will be left with little more than a stiff back, which does not prevent general mobility. However, the importance of exercise, healthy eating to prevent obesity and maintaining good posture cannot be stressed enough.

Medical treatment

The aim of medical treatment is to relieve pain and inflammation. A variety of medicines are available. Unfortunately, the main group of anti-inflammatory drugs, NSAIDs are known frequently to make IBD worse and are therefore better avoided. Sulphasalazine, by contrast is valuable in the treatment of inflammation both of the joints and in the gut, although it may sometimes produce allergic side effects. 
Local heat such as hot water bottles or heat lamps to an affected area may provide pain relief.


Occasionally surgery may be carried out to provide movement in damaged hip joints. 


Episcleritis is inflammation of the outer layers of the sclera (tough white layers of the eyeball).

What is the cause?

It usually occurs in flare-ups of inflammatory bowel disease and is more common in CD (3 – 4%).

What are the symptoms?

The commonest presenting symptoms include:

  • burning or itching eyes
  • watery eyes

Examination of the eyes shows redness of the eye due to an increase of blood vessels (hyperaemia).

What is the treatment?

Topical steroid preparations may help relieve symptoms quickly, but steroid tablets may be more continuously effective.
As the condition usually occurs with disease activity, controlling intestinal disease will relieve symptoms. 

Erythema Nodosum

Erythema nodosum is a skin condition causing red, raised, tender nodules on the legs. They usually measure between 1 – 8cm. 

What is the cause?

They tend to be associated with inflammatory bowel disease and are more common in CD (up to 15%) than Ulcerative Colitis (UC).

They tend to occur as the disease is active but may occasionally be the presenting symptom of the disease. It also occurs commonly with arthritis and inflammation of the eyes.

It tends to be more common in women and is also the commonest extra-intestinal symptom in children.

What is the treatment?

As the condition is associated with active disease, controlling the underlying disease will usually relieve the skin lesions. 

Perianal Complications of CD

Around 30% of patients with Crohn’s disease will suffer perianal complications of the disease, such as:

1. Skin lesions
These include:

  • Excoriation (redness and soreness) due to diarrhoea
  • Skin tags
  • Ulcers and abscesses just beneath the skin

2. Anal canal lesions
These include:

  • Fissures (painful cracks)
  • Ulcers
  • Stenosis (narrowing of the passage)

3. Fistulas
A fistula is an abnormal passage between two adjacent organs. Those around the anus usually link the rectum to the outside skin and are called fistulae-in-ano. They may be low, high or recto-vaginal.

Approximately 10-15% of patients with Crohn’s disease initially present with perianal symptoms. Further investigation confirms the diagnosis.

Treatment usually involves treating the underlying disease thus improving perianal symptoms. Anal lesions, particularly skin tags and fissures, can often look unsightly but apart from occasional bleeding may be relatively painless. Under these circumstances surgery should be avoided as it often leads to painful sores that are very slow to heal. With the aid of conservative medical treatment one should try to live with the condition.

However, to determine if more extensive intervention is required, further investigations may need to be carried out. These could include:

MRI scanning
This is one of the most accurate techniques for showing the extent of complex fistula tracts around the anus and detecting unsuspected abscesses. It is a painless procedure without risk of radiation.

This may be either with a rigid or a flexible tube. The advantage of the flexible tube is that it can view further but needs to be carried out in the Endoscopy Department, rather than at an out-patient clinic.

Examination under anaesthetic
It is sometimes too painful to perform a successful rectal examination and therefore an anaesthetic may need to be given in the operating theatre.

  • Analgesics (painkillers) either by tablet or local anaesthetic creams or gels applied directly to painful fissures.
  • Antibiotics used to control infection and assist healing, (e.g. metronidazole, ciprofloxacin, tetracycline co-amoxiclav). There is often a relapse when medication stops, so smaller maintenance doses may be needed.
  • Anti-inflammatory drugs (e.g. sulfasalazine, mesalazine, prednisolone). As with antibiotics there is often a relapse when medication stops.
  • Immunosuppressive drugs (e.g. azathioprine,methotrexate).
  • Infliximab. This may allow many fistulas to close up. However, closure of the end of a fistula does not necessarily mean the internal tract has been eradicated. Many surgeons fear that abscesses may arise if drainage of the tract is prevented by closure of the opening. Further research continues.

  • Analgesics (painkillers) either by tablet or local anaesthetic creams or gels applied directly to painful fissures.
  • Antibiotics used to control infection and assist healing, (e.g. metronidazole, ciprofloxacin, tetracycline co-amoxiclav). There is often a relapse when medication stops, so smaller maintenance doses may be needed.
  • Anti-inflammatory drugs (e.g. sulfasalazine, mesalazine, prednisolone). As with antibiotics there is often a relapse when medication stops.
  • Immunosuppressive drugs (e.g. azathioprine,methotrexate).
  • Infliximab. This may allow many fistulas to close up. However, closure of the end of a fistula does not necessarily mean the internal tract has been eradicated. Many surgeons fear that abscesses may arise if drainage of the tract is prevented by closure of the opening. Further research continues.

  1. Incontinence
    Faecal incontinence may occur due to:
    • Incompetent anal sphincter as a result of previous surgery
    • Loose stool
    • Age and poor control

      This may be managed by administration of bulking agents, such as preparations of ispaghula,(Fybogel, Isogel, Metamucil, Regulan) sterculia ( Normacol), or methyl cellulose (Celevac) together with an anti-diarrhoeal agent, such as loperamide (Imodium) or codeine phosphate.

      The formation of a ‘plug’, made out of toilet paper and inserted just inside the anus, may prevent soiling of the underwear. Various sized pads, to wear inside the underwear, are also commercially available.


Diarrhoea and leakage from the anus may cause soreness and irritation. Frequent warm baths, showers or the use of a bidet, should be taken particularly after having bowel movements. Plain, moist tissue wipes are gentler and less abrasive than toilet tissue. 

Following bathing, gently patting the perineum with a towel, or use of the ‘cold shot’ setting on a hair dryer will be less traumatic to the tissue. Try to ensure that the anus is dried completely. 

Conservative Surgical Management

Surgical treatment of perianal disease may be required if symptoms persist despite medical treatment. Disadvantages of surgery include poor healing rates and risks of incontinence. However, it may be necessary to treat abscesses or fistulae surgically. 

Abscesses may require incision and drainage if there is pain and inflammation caused by pus under pressure.

Fistulae may require incision and drainage either with a small tube or a draining seton (a small stitch) which holds the tract open allowing it to drain. These may be left in for several weeks or months.
Many studies show that the degree of rectal involvement in CD has an influence on the success rate of surgical management. The greater the inflammation, the poorer the response.

Rectal strictures are often associated with long-standing disease and periodic dilation may help. This may be continued manually with an anal dilator in varying sizes.

Faecal diversion, i.e. colostomy or ileostomy remains a controversial procedure. However, may be very valuable in the presence of severe peri-anal disease to allow healing of perianal infection, although relief may only be temporary. If chronic ill health and incontinence have caused major inconveniences to daily living, faecal diversion may provide a better quality of life.

Peripheral Arthritis in Inflammatory Bowel Disease

This is the most common extra-intestinal manifestation of inflammatory bowel disease and occurs in around 20% of patients. 

In UC it tends to be associated with flare-ups of the disease but CD it is usually less severe and can occur independently of the state of the intestine.

It tends to move from one joint to another (migratory) and can affect a single joint or several joints at a time. The larger joints are more commonly affected, i.e. knees, hips and ankles, but wrists and elbows may be affected also.

What are the symptoms?

The joints become inflamed causing:

  • Effusion (fluid in the joint)
  • Swelling
  • Redness
  • Pain and tenderness over the joint 

What is the treatment?

Some treatments for arthritis may make the Crohn’s worse, e.g. NSAIDs, (See list here) which can cause diarrhoea and erosion of the gut mucosa. Some other treatments which may help include:

  1. Simple painkillers such as soluble paracetamol
  2. Local heat or ice packs to the affected joint
  3. Resting the affected joint
  4. Gentle exercises planned by a physiotherapist
  5. Aspiration of fluid from the joint, relieving pressure and therefore pain
  6. Injection of steroids into the joint
  7. Anti-inflammatory drugs such as Sulfasalazine

The symptoms may settle down with control of the underlying inflammatory bowel disease. Other conditions such as uveitis and erythema nodosum may also be associated with flare-ups of the arthritis.

Pyoderma Gangrenosum

Pyoderma gangrenosum is a chronic skin ulceration occurring usually on the legs but can appear anywhere on the body. The pain may be apparent before the ulcers appear and they may also drain pus-like fluid but are not usually infected.

What is the cause?

The condition is usually associated with IBD and is more common in UC (1-5%) than CD (1-2%). It is also often related to an injury, or following an injection in the affected area. It can occur independently of active disease although pancolitis is found in 85% of patients with the condition.

What is the treatment?

Treatment of the underlying inflammatory bowel disease is often successful in resolving the skin lesions.

Medical treatments may be tried, such as:

  • Topical antibiotics
  • Corticosteroids
  • Azathioprine
  • Cyclosporin and other immunosuppressive drugs.

However, the lesions may return. Colectomy provides a cure in most cases of persistent, troublesome lesions.

Recto-Vaginal Fistula

A recto-vaginal fistula is an abnormal opening between the rectum and vagina which allows the passage of small amounts of waste, normally contained in the rectum, to pass into the vagina leading to possible infections and unpleasant vaginal discharge. 

What is the cause?

The major cause is chronic active inflammation in the bowel, particularly CD.

What are the symptoms?

The main symptom is passage of flatus (wind) through the vagina. There may also be vaginal discharge.

How can it be treated?

Treatment tends to depend on the severity of symptoms and effect on quality of life.

  • Minimal symptoms (i.e. passing wind through the vagina) would need no intervention unless it became a problem to live with.
  • Other fistulae, complicated by pus and rectal disease causing perianal discomfort, may require more vigorous treatment such as:
  1. Drainage
    • Insertion of a seton (a stitch) between the rectum and vagina, allowing drainage to occur as the tract is kept open.
    • Insertion of a small drainage tube into the tract.
  2. Antibiotics
    (e.g. metronidazole)
  3. Bulk laxatives
    (e.g. Normacol, Celevac.)
    It is helpful if the stool is kept firm so as to reduce the likelihood of faecal fluid contaminating the vagina.
  4. Antidiarrhoeal agents 
    (e.g. Loperamide)
    Greater effects can be achieved when a bulk laxative and an antidiarrhoeal agent are taken simultaneously.
  5. Vaginal douching

It is occasionally possible for surgeons to attempt to repair the fistula, although it is generally considered better to leave them alone as they can be made worse. However, surgical techniques have improved and if problems persist giving a poor quality of life, surgery may be discussed. 

The repair can usually be performed in several ways:

  • Transanal (through the anus)
  • Transperineal (the skin between the vagina and rectum)
  • Transvaginal (through the vagina) 

The success of repair techniques is dependent on the following factors:

  1. The presence of proximal Crohn’s disease (disease next to the fistula)
    This tends to give poor results and active disease should be treated prior to surgery.
  2. Associated infection at the time of operation
  3. Whether a temporary stoma is used
  4. The degree of rectal involvement
  5. Current drug treatment

Will it come back?

Fistulae can return, either as a consequence of failed surgery or due to a relapse of the disease.

What about menstruation?

The amount of discomfort experienced will determine whether to use tampons or sanitary towels during the menstrual period. If tampons are used, it is important to remember to change these frequently and regularly.

What about sex?

Sexual intercourse will not make the fistula worse, but may be uncomfortable. Sex may seem inappropriate in the presence of an unpleasant discharge, but many couples find that the use of a condom is sufficient to overcome this difficulty.

As most recto-vaginal fistulae are low in the vaginal wall, a diaphragm (or Dutch cap), may still be a suitable method of contraception. Take medical advice on this.

Sclerosing Cholangitis

Sclerosing cholangitis is an inflammatory disease causing fibrosis (stiffening) of the bile ducts both inside and outside the liver and hampering the flow of bile. It may eventually lead to jaundice or cirrhosis of the liver.
It is a rare disease that may be associated with IBD, particularly UC (around 1-4%).

How is it caused?

The cause is unknown but certain factors have been suggested to play a part in its development, such as:

  • toxins, derived from bacteria in the gut or environmental
  • increased copper in the liver
  • viral infections
  • genetic susceptibility 

What are the symptoms?

The disease may be present for many years without symptoms, but may eventually show signs of:

  • jaundice
  • pruritis (itchy skin)
  • abdominal pain
  • enlarged liver
  • gastrointestinal bleeding

It is frequently first detected by abnormal blood tests revealing liver damage. 

It tends to occur more commonly in men and after 30-50 years of age and the risk of cancer developing in the bowel is increased significantly in patients with sclerosing cholangitis and careful follow up of these patients is essential.

What is the treatment?

Treatment is both medical and surgical.


Few drug treatments have been effective in sclerosing cholangitis other than supplements of Vitamin D and Calcium to prevent osteoporosis and reduction of bone cells.
Endoscopic retrograde cholangio pancreatography (ERCP) and balloon dilatation of the bile duct strictures have sometimes been successful in reducing hospital admissions and improving blood results.


This is generally a means of bypassing the strictured ducts, inserting stents (small plastic drainage tubes) to keep the ducts patent or, ultimately, a liver transplant. 

Strictures in Inflammatory Bowel Disease

A stricture is a narrowing of a portion of the bowel caused by periods of inflammation and healing, leading to formation of scar tissue. This then causes a slowing of, or an obstruction to the intestinal flow. Strictures may be caused by inflammatory changes, when swelling of inflamed tissues leads to narrowing of the bowel, or by fibrosis, where scarring is the cause of the stricture. Inflammatory strictures may resolve rapidly after effective treatment; fibrotic strictures on the other hand are unlikely to improve with medical treatment alone, and usually require endoscopic dilatation or surgical removal.

Where do they occur?

They tend to be more common in people with CD, but can occur in around 6 – 11% of patients with UC. The most common site for a stricture to occur is the terminal ileum. Other frequent sites may include the rectum and the transverse colon.

What are the symptoms?

These may be variable depending on the site of the stricture, but most often include:

  • abdominal cramps
  • pain after eating
  • nausea and vomiting
  • constipation
  • Very narrow strictures may obstruct the passage along the gut leading to intestinal obstruction, an emergency which causes severe pain, vomiting and constipation. 

The presence of a stricture can be confirmed by x-rays or endoscopy.

Can it be cancerous?

Strictures are not usually cancerous but some may not easily be distinguished from cancer. Therefore it may be necessary to perform x-rays and endoscopy with biopsies.
Patients with long strictures of which adequate examination cannot be made, may be advised to undergo surgery.

How are they treated?

Many strictures are not sufficiently narrow as to cause symptoms, and may safely be left alone. However, they appear to act as a surface on which bacteria can lodge, for recurrence of disease usually occurs at the upper (proximal) end of the stricture, and persisting inflammation, which could make the stricture narrower, may be a reason to take action. Strictures may be treated either medically or surgically.

Medical management

If the stricture is not too narrow, a modified diet to reduce the risk of blockage by lumps of food, (i.e. no coarse fibre and small, regular meals), and drug therapy may continue. Immunosuppressive medication may be very effective, and antibiotics are sometimes valuable for persisting proximal inflammation. Dietary treatment of Crohn’s will often dramatically improve inflammatory strictures but has little effect on fibrotic ones. 

Surgical management

Many fibrous strictures eventually require surgical management. The stricture may be improved at endoscopy by passing a balloon catheter through and then inflating it so dilating the narrow portion. This form of treatment depends on the site and length of the stricture and the absence of abnormal histology. It may have to be repeated several times on different occasions to be fully effective. Some may be relieved by a surgical procedure known as stricturoplasty, when the surgeon makes a longitudinal cut along the strictured piece of bowel which he then stitches up again transversely thus widening the bowel. Long strictures may require resection – which is cutting out the affected loop of bowel and re-joining the cut ends (anastomosis). provides general information only and should not be regarded as a substitute for medical advice from your own doctor or healthcare provider.
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