A much misunderstood and stigmatised condition, Crohn's Disease falls under a group of large bowel diseases called chronic inflammatory bowel diseases of unknown cause. Just how it is caused is unknown, and much research is being directed at how best to treat its symptoms and what kicks it all off in the first place.

A Short History

As medicine was first beginning to become respectable as a profession in the 19th Century, there were numerous reports of a Crohn's-like disease throughout literature. In 1806, although the disease was nameless, doctors Coombe and Sanders presented what has been widely regarded to be the first case of Crohn's to the Royal College of Physicians, England.

Various other physicians and surgeons also documented the disease, but it was not until 1932 that what has been described as a landmark paper was published, that the disease was pushed into the limelight.

Research conducted at the Mount Sinai Hospital, New York, on a condition known then as 'terminal ilitis' prompted further research into the cause of the condition. The three-man team of doctors were on the case; doctors Burrill B Crohn, Leon Ginzburg, and Gordon D Oppenheimer.

Most cases of this 'terminal ilitis' were lumped in together with a different condition - intestinal tuberculosis. What was intriguing was that in some cases of terminal ilitis, there was no obvious bacterial cause. In fact, it was a failure of the team to find a definitive cause which made the eventual paper 'Regional Ilitis' so groundbreaking.

Yet the disease still had no name. The reason why it was called Crohn's disease is rather an uninteresting one. As all the authors of a paper are listed in alphabetical order, Dr Burrell B Crohn's name was the first on the list. Physicians in England, for want of a less ominous name than 'terminal ilitis', nicknamed the condition 'Crohn's Disease'. From there on in, the nomenclature spread, and it has now passed into normal medical terminology.

Epidemiology

Crohn's Disease is more common in those of European origin, and those in temperate climates. The incidence of the disease has been increasing steadily from the 1960s, until it reached a plateau in the '80s, of 2-5 new cases per 100 000 people in the UK every year.

The most commonly affected age groups are:

• 20-29
• 50-59
• 70-79

The 20-29 age group consist of the largest group of sufferers.

Cause

Unknown, although many possible theories have been put forward:

Infection

The culprit put forward for this theory is a mycobacterium, due to the type of inflammatory response which is seen time and time again in the gut. Also, several gut biopsies have shown the presence of this type of bacteria in several Crohn's patients. However, not all of those who suffer from Crohn's have this bacteria in the affected part of their gut, and as of yet, no proven link lies to link an infectious assault on the gut to kicking the whole thing off.

Genetic

It has been shown that there has been some familial link in Crohn's, with identical/non-identical twin studies suggesting a strong link. The genes involved are those which govern immunity, and the ability of the immune system to distinguish between cells of the body, and foreign cells. Modification of these genes leads to some difficulty in making this distinction, and thus, a state of auto-immunity - where the body attacks itself. This was also shown by an increased immune response in the affected segments of gut, suggesting that this may play a part in the disease progression of Crohn's. However, as with infection, the genetic link may be strong, but it is far from conclusive. There are many people with this gene who do not have Crohn's at all.

Environmental

So to the last theory - the environment. Several studies have shown that there is an association with smoking and Crohn's, and indeed, smoking can make it much worse. How it works, no one really knows. Again, this is not to say that if you smoke, you will get Crohn's - as there are lots of smokers who will never get Crohn's, and conversely, lots of non-smokers who have never smoked in their lives who have Crohn's. So once again, this factor must contribute, but can't be singled out as a definitive cause.

As with all things, stress has been shown to be a major contributing factor to at least, the exacerbation of Crohn's.

What Does it Do to the Gut?

Being an inflammatory bowel disease, its main effect is to make sections of the bowel inflamed. There is a characteristic way in which it does this:

• Whole gut - Your gut runs from your mouth to your anus, and Crohn's can affect any bit of it. This means that a person will often have ulcers in the mouth, a painful anus, and an exquisitely painful abdomen.

• Skip lesions - The ulcers don't occur in continuity - ie, all along one section of gut. Instead, they 'skip', forming lesions in one bit, with a bit of normal bowel in-between, and then another lesioned bit.

Clinical Features

Symptoms

Crohn's is a relapsing-remitting disease, so the greatest problem for those who suffer from this disease is that they may be well for several years, and then have an attack, where the bowel just inflames for no reason. What will happen is that the sufferer will often present themselves to the local Accident and Emergency department, complaining of these symptoms:

• Excruciating abdominal pain, most commonly in the lower part of the abdomen, on the right-hand side, or generally all over the tummy. It will be very tender, and quite debilitating.

• Pain on eating, relieved by defecation - the stools being quite loose, and depending where the lesion is, blood in the stools¹. Defecation may be very painful.

This may go on for weeks or months at a time, before resolving of its own accord.

Investigation

A barium enema is very good at showing up segments of inflamed bowel, but a good way of confirming Crohn's for the first time may be to use an endoscope to look all around the bowel. Biopsies may be taken of the rectum to confirm inflammatory changes, and to distinguish it from the other cause of acute abdominal pain, appendicitis.

Management

Unfortunately, just as the cause is elusive, so is any medical treatment. Nothing has been shown to be effective, and most treatment is directed at the symptoms - so reducing the inflammation by using anti-inflammatory drugs such as steroids has been shown to provide some relief in the short term, but the use of immunosuppressives like those used in rheumatoid arthritis² haven't been as successful as previously thought.

Surgery is at best avoided as if a section of affected gut is removed, then the disease can recur in an entirely normal section of remaining gut. Of course, the surgeon could then keep cutting, but then you could be left with potentially no gut left. This avenue is regarded to be the very last resort.

Several diets have been put forward to try and shorten these periods of 'flare-up', but as of yet, nothing at all, drugs, diet, surgery have all been unsuccessful. Trials of antibiotics are currently going on, but again, they are of doubtful value. Sadly, there is nothing which can prevent a relapse.

Complications

Fistulae

When things get inflamed, they get quite sticky. So the bits of inflamed bowel in Crohn's may get stuck to the surrounding structures, such as other bits of normal bowel, the bladder, or, in women, the uterus/vagina. What may then happen is that an abnormal communicating channel may break through, connecting these two structures together. This is called a fistula, and the only way around this is surgery. The offending section of bowel is taken out.

Strictures

After a bit of bowel is subject to inflammation, recovery and inflammation again, scarring may occur. What may then happen is that that section of bowel may narrow - forming what is known as a stricture. Here, a more conservative approach is taken. The narrow segment is enlarged by blowing up a small balloon, and leaving a small cylindrical wire mesh inside to keep it open.

Cancer

This is a disease which involves sections of bowel being repeatedly inflamed. This can unsurprisingly lead to some changes at the cellular level. As a late result, Crohn's sufferers have an increased risk of cancer within the gut. Hence why those who suffer from Crohn's are screened via endoscopic biopsy every now and again so that any suspicious changes can be seen early, and treated quickly.

Crohn's - One Researcher's Experience

It may be all well and good describing the condition from the foot of the bed, but how is it from the person who has to lie in it?

Here is one Researcher's experience of the condition, which has been described by their consultant as, 'something you wouldn't wish on your worst enemy'.

Diagnosis

A serious difficulty that sufferers face is getting properly diagnosed in the first place, particularly as it often first appears in young adults, who are supposed to be healthy. It is often confused with Irritable Bowel Syndrome, which is a completely different condition which is much more common, and has some similar symptoms.

In my own case it took two doctors, eight separate visits, five types of medication, and four stone of weight loss before I finally managed to get so much as a blood test. By this time, people I barely knew would stop me and ask if I was all right, and the doctor's receptionist didn't have to ask my name anymore when I arrived. I was in constant pain, couldn't eat or sleep, and was probably only days away from needing hospital treatment.

The final straw was when I dragged my disease-ravaged frame to see the doctor and was on the verge of being prescribed peppermint tablets, which would 'sometimes help'. I wish I'd read this entry on how to get a doctor's attention.

Finally getting a proper diagnosis was actually quite a relief, as this meant that I had a right to be feeling dreadful (rather than being a hypochondriac with a low pain threshold and irritable bowel syndrome), and also introduced the faint and distant possibility of something actually being done about it.

Fun with Steroids

Crohn's Disease is often treated with prednisolone steroids. These aren't performance enhancing drugs (in fact rather the opposite), but are quite effective, however with some unusual side affects. One of which is the appetite of a very large horse who's just finished a 24 hour charity fast.

I was regularly eating five or six meals a day, which was a big improvement from five or six meals per week. It felt very strange and (for a student) was very expensive, and involved spending most of the money I'd saved by not eating! Breakfast, lunch, afternoon snack, evening meal, bedtime meal. Very, very weird! It was quite nice in some ways, to be able to enjoy food again, to (mostly) keep it down, and to be able to feel unclouded, uncomplicated hunger, without the shadow of impending agony.

Even more bemusing was the listed side effect 'mild euphoria'. This unnerved me, because it meant that I couldn't be sure whether I was happy because I was feeling a bit better and it was spring, or because I was absolutely off my face on drugs. With hindsight, I believe that I spent several weeks wandering around grinning at everyone and eating anything that wasn't nailed down or a pot noodle.

What to do if a friend has Crohn's Disease

Crohn's Disease can be embarrassing - it involves digestive abnormalities which are not usually the topic of polite conversation - and your friend may be reluctant to talk about it, or even tell you.

Someone with active Crohn's Disease is likely to be in a lot of pain most of the time. Sometimes sufferers will want to go and curl up in a corner and wish they were dead, but other times will want distraction and company. Bear in mind that anything food related could be tricky, as could any activities that involve being any distance from a bathroom. Sufferers are often low on energy, partly through low iron levels in the blood³, and partly because of a reduced calorie intake, so sports or strenuous activities are not a good idea.

Different people react to illness in different ways, but it was my experience that just being around people was very helpful. I didn't want to be constantly asked how I was (though a bit of concern never went amiss), I wanted to talk about other things (or, more often, just listen to others talking). A bit of distraction goes a long way!

Support Groups

• National Association for Colitis and Crohn's Disease (UK)
• Crohn's and Colitis Foundation of America (US)