Irritable bowel syndrome

Chronic relapsing illness. Empathetic and supportive care is important

About

• IBS can cause severe symptoms
• Expert empathetic management is key to reducing symptoms

Aetiology

• IBS typically decreases with age. It is called a functional illness as there are no real demonstrable pathological findings. However, that is not to say that the illness is "imaginary".
• Test have shown some degree of visceral hypersensitivity. IBS may be regarded as part of a functional gastrointestinal disorder - a dysregulation of "brain-gut function".
• Patients do suffer and deserve empathy and consideration and an attempt at symptoms control. IBS also is an expensive illness as it causes sickness and work absence. It is seen more commonly in women. There is increased anxiety and depression scores in sufferers.

Clinical

• Clinical history usually has lasted at least 6 months of symptoms
• Abdominal pain is usually variable but tends to be relieved by defecation
• Incomplete evacuation is a typical complaint
• The passing of mucus per rectum
• Abdominal bloating, Nausea alone or vomiting alone
• Extracolonic symptoms e.g. heartburn
• Extra-GI tract features such as atypical chest pain, globus hystericus

May be divided by clinical history into different types

• Diarrhoea predominant
• Constipation predominant
• A mixture of both with patients flitting between types at different times

Important to consider alternative diagnoses

• Red flag symptoms suggesting further investigations such as colonoscopy for polyps, malignancy and diverticular disease or abdominal CT or small bowel investigations and screening for coeliac disease etc
• Anaemia, Fever, Weight loss
• Rectal bleeding
• Nocturnal GI symptoms
• Family history of GI cancer/Inflammatory bowel disease/Coeliac
• New onset age > 50

Investigations

• There are NO specific biochemical and structural abnormalities that explain symptoms and this is part of the definition of IBS.
• Consider FBC, ESR, CRP, Anti endomysial ab, TFT's, LFT's, U&E
• If suspicions of colorectal disease - colonoscopy and stool culture. Sigmoidoscopy and air insufflation may recreate some of the symptoms.
• If suspicions of Upper GI disease - OGD + duodenal biopsies

Management

• Reassurance and consideration of psychosocial and other factors
• High fibre diet can be helpful
• Antispasmodics such as Mebeverine can be useful
• Psychology - Biofeedback and antidepressants and other therapies have been used with mixed results
• Cognitive behavioural therapy and relaxation techniques may help

Rome II 1999 Diagnostic criteria

These criteria state that in the preceding 12 months there should be at least 12 weeks (consecutive) of abdominal discomfort or pain that has two of three of the following features:
• relieved with defecation; and/or
• onset associated with a change in frequency of stool; and/or
• onset associated with a change in form (appearance) of stool.

The following symptoms cumulatively support the diagnosis of IBS:

• abnormal stool frequency (defined as > 3/day and < 3/week)
• abnormal stool form (lumpy/hard or loose/watery stool)
• abnormal stool passage (straining, urgency, tenesmus)
• passage of mucus
• bloating or feeling of abdominal distension.