The post I wrote last week, ‘Stuck, when your bowels rule your life’, raised a bit of a storm. Several people wrote into Facebook to assert how much worse Crohn’s Disease was than IBS and others countered by exclaiming just how bad their IBS was. But how can we compare the one person’s illness experience with another’s? It is purely subjective and therefore cannot be measured accurately. Scientists may use ‘objective’ measures of disability or illness behaviour to determine Health Related Quality of Life (HRQoL) assessments, or economic indices to assess ‘Well being’, but these rely on unproven assumptions. Illness is an emotional experience that bears little relationship to any physical measure of disease. Recent reports show that patients with Inflammatory Bowel Disease (IBD) have very similar HRQoL scores compared with people who have IBS. Psychological distress is also about the same , whereas the severity of recent stressful life experiences was perceived to be higher by IBS than by IBD patients.
In my response to the comments on Facebook, I confirmed that, from the perspective of a gastroenterologist, Crohn’s appears to be a dreadful disease with all kinds of painful, embarrassing and life threatening complications. But people with IBS can also be severely afflicted by pains that are so awful they cannot do anything, diarrhoea that does not let them go out of their house, bloating so bad they can scarcely breathe. The degree to which people ‘feel’ ill is not related to the degree of tissue damage. People with IBS may feel just as ill as people with Crohn’s Disease, yet the degree of colonic inflammation is nowhere near as extensive as in active Crohn’s Disease. Moreover, they suffer the insecurity of an inexplicable disease, for which they feel stigmatised and blamed. People with Crohn’s Disease also have symptoms of IBS. The prevalence of IBS-like symptoms in IBD patients in long-standing remission is two to three times higher than that in the normal population. The point is that the physical and emotional consequences of both conditions can wreck lives.
Illness or ‘malaise’ is a combination of non-specific symptoms that includes intense fatigue, muscular weakness, faintness, nausea and pain, but these are overlaid by a combination of anxiety and depression that induce feelings of powerlessness and hopelessness. This constellation of feelings dominates our whole attention. We cannot think of anything else if we are ill. If we try to do anything, we feel worse. Illness saps any initiative; all we can do is lie down and rest.
Symptoms of illness may be triggered by bodily damage and may be referenced to a particular part of the body, but it is the brain that generates the sensations of illness and initiates the behavioural changes that are conducive to healing. For example, nausea is generated by activity in diffuse neural connections in the brain stem. tiredness is also generated in the midbrain and hindbrain, while pain is generated in the thalamus and anterior cingulate cortex and only projected into the part of the body that hurts.
But not all illness is triggered by events in the body. Fatigue may be caused by overwork, excessive or prolonged activity, but may also represent a psychological lack of motivation, the feeling we get when we try to force ourselves to do something we don’t want to do. Pain can be perceived in parts of the body, where there is no sign of any damage. The pain of a headache is often related to tension in the muscles at the back of the neck, brought about by continued emotional pressure. A similar phenomenon occurs in backache. Amputees can feel pain in the fingers of the arm that has been removed. People, whose gall bladder has been resected may still continue to feel the symptoms of cholecystitis. Pain is encoded in our long term memory and can be evoked by anything that reminds us of the circumstances of the surgery or the injury as well as some emotional trauma with bodily connotations. The same applies to nausea and to tiredness. Antidepressants can suppress the malaise of many unexplained illnesses. Morphine reduces the breathlessness in heart failure and is said to suppress feelings of impending doom.
So what causes the symptoms of malaise? Many research studies suggest that cytokines, pro-inflammatory transmitters, play a key role. When the cells of our bodies are damaged by an infection, injury, cancer, toxins, lack of blood supply or has just begun to deteriorate, they release transmitter substances that not only cause a local inflammation and excite the immune system but also affect our central nervous system to alert us to the damage and compel us to rest and allow healing to take place. The immune system communicates directly with the brain, causing depression and activating the systems that react to stress. So anything that releases cytokines in sufficient quantitities can cause illness. This might be actual tissue damage or it might be exhaustion, putting oneself under pressure or eating or drinking too much. Alcohol can cause all the features of illness, but is this the direct toxic effects of acetaldehyde or the release from cytokines from an inflamed liver? Exhaustion causes nausea and headache as well as terminal fatigue. Just the thought of an injury can light up the relevant areas of brain and release pro-inflammatory transmitters from the target organ. Stress causes the release of proinflammatory cytokines and increased the risk of allergies, reduces wound healing Experiments have shown that injections of cytokines can cause all the features of illness, while anti-inflammatory drugs such as steroids or aspirin can suppress the release of cytokines and reduce feelings of illness.
So just because the cause of IBS is not clear, does not mean that mean that it is insignificant or does not have some immunological or physiological change. People should not be regarded as weak or neurotic or imagining an illness, and in 45 years of medical practice, I have never met a patient with symptoms of IBS who was putting it on. I have, however, met people whose illness commenced with an attack of gastroenteritis, listened to many people who have suffered the most traumatic circumstances, helped some reduce the impact of their symptoms with diet, medication and advice on managing stress, and seen a few who turned out to have Crohn’s Disease. But whatever is causing the symptoms, people with IBS deserve to be treated with dignity and understanding, not just by doctors but by people in general. Only then will they have the support and attention that will help them get better.