Irritable bowel syndrome is a very common problem in primary care affecting nearly all sections of the population. Although it is a functional bowel disorder, it significantly affects the day to day activity with morbidity. It usually presents in three forms
- Abdominal pain and bloating relieved by defecation.
- Predominant diarrhoea.
- Predominant constipation
While dealing with IBS, one should exclude more serious organic causes of altered bowel habits.
- Infective diarrhoea – It is very common in USA. Chronic amoebiasis and amoebic colitis can cause similar symptoms. There may be the history of bloody diarrhoea, tenesmus and increased mucus in the stool. Stool examination may not reveal cysts of amoeba. A course of ciprofloxacin and metronidazole may be tried as a therapeutic measure.
- Inflammatory bowel disease – This condition is increasingly being detected since the use of colonoscopy in investigation of chronic diarrhoea. Usually, there is weight loss, blood in stool, nutritional deficiency. Markers of inflammation like ESR and CRP are y raised.
- Bowel malignancy – In elderly patients presenting with altered bowel habits, loss of weight – and blood in the stool, malignancy of the large gut needs to be excluded. Haemoglobin will be low. ESR and CRP will be elevated.
- Lactose intolerance – It is relatively common in certain parts of USA. A trial of exclusion of milk should be tried if suspected. However, lactose intolerance only becomes symptomatic if more than 280 ml of milk is consumed.
- Malabsorption due to any cause should also be excluded by doing appropriate stool tests and blood tests. Coeliac disease although uncommon in USA should be considered in western population. Antigliadin and anti-endomysial antibodies should be requested for if clinically suspected. Chronic pancreatitis with abdominal pain and malabsorption can cause diagnostic confusion.
- Medical disease like thyrotoxicosis can cause diarrhoea and should be excluded.
Alarm signals suspected in IBS are:
- Progressive anaemia.
- Blood in the stool.
- High ESR and CRP.
Investigation in suspected IBS:
- Stool for routine and culture and occult
- Hb, TC, DC, Platelet, ESR, CRP.
- Liver function test.
- Amylase, Lipase.
- Thyroid function test.
- Antigliadin and anti-endomysial antibodies in selected population)
- Urea, electrolytes, calcium, folic acid, ferritin.
is there weight loss with bloody diarrhoea or recent onset of constipation and weight loss middle-aged and elderly patient, colonoscopy should also be considered.
Diagnosis inflammatory bowel disease.
High fibre diet along with increasing dose of isabgol husk will be needed. Osmotic laxative may also be added. One should try to avoid stimulant laxatives.
Infection should be excluded and treated with appropriate antibiotics. Loperamide and diphenoxylate may be used to control diarrhoea. Morphine containing preparations may be used but they can cause rebound constipation.
Abdominal pain and bloating –
Prokinetic agents will be helpful. Cisapride but not metoclopramide or domperidone decrease colonic transition time. Unfortunately, the use of cisapride has been stopped following reports of fatal cardiac arrhythmia. Anticholinergic like mebeverine is a
commonly used drug with some beneficial effects. Treatment of depression and anxiety –
This is very important and SSRIs are perhaps better than tricyclics in view of the later’s constipating effect. Psychiatric counselling may be required. The patient must be reassured that although chronic and persistent, it does not have any effect on mortality and should be given an optimistic picture.