Irritable bowel syndrome is the commonest primary care hindgut condition. The well established Rome criteria based on clinical symptoms help to diagnose it.
Abdominal pain that gets better on defecation. When the pain comes on there is a change in frequency or change in form of stool.
There is abnormal stool frequency (more than three times a day or less than twice per week). The form may change from lumpy/hard to loose/watery. The patients notice a change in passage i.e. strain, urgency, tenesmus.
Patients have bloating which is often relieved on opening bowels. There may be passage of mucous per rectum.
Finally there is often association with stress and anxiety.
What tests should I do for a change in bowel habit/diarrhoea?
Routine biochemistry, Full Blood Count, ESR, CRP, TFT's. Tissue transglutaminase (including immunoglobulins) if diarrhoea is a prominent symptom.
Consider stool culture if infection is suspected.
Faecal Elastase 1 for pancreatic disease.
Colonic imaging. Colonoscopy is the gold standard for colonic imaging - it is diagnostic (direct visualisation and biopsies of the large bowel and terminal ileum) and well as well as therapeutic (principally polyp removal). CT pneumocolon is an alternative promising investigation that is less invasive. However, it is purely diagnostic and does not allow the taking of mucosal biopsies/removal of polyps.