Irritable Bowel Syndrome

Irritable Bowel Syndrome

1. Symptoms & Signs

   • Symptoms: Central/lower abdo pain relieved by defecation, abdo bloating, altered bowel habit (constipation & diarrhoea), tenesmus, mucus PR. Symptoms are chronic (>6months), exacerbated by stress, menstruation, gastroenteritis. Signs: Examination often normal, may see generalised abdo tenderness, insufflations of air during sigmoidoscopy may reproduce pain.
   • Markers suggesting other disease
     • Age >40yrs, hx <6months, anorexia, weight loss, waking at night with pain/diarrhoea, mouth ulcers, abnormal investigations (ie raised CRP, reduced Hb). PR bleeding - investigate urgently.

2. Investigations

   • Young with classic hx
     • FBC, ESR, LFT, celiac serology, urinalysis +/- sigmoidoscopy with rectal biopsy
   • >45yrs/any marker of organic disease
     • colonoscopy and if unavailable then barium enema
   • Prominent diarrhoea
     • LFT, stool culture, B12/folate, anti-endomysial antibodies, TSH, consider referral +/- barium follow-through +/- rectal biopsy (if symptoms suggest small bowel dis).
   • Further investigations, guided by symptoms
     • Dyspepsia/reflux = upper GI endoscopy. Coeliac suspected and anti-endomysial antibodies +ve = duodenal biopsy. Potential infection = giardia tests. Crohn’s suspected = small bowel radiology. Chronic pancreatitis suspected = ERCP. Active pancreatitis suspected = MRCP
   • Refer
     • If either: equivocal diagnosis, changing symptoms in known IBS, refer to surgeon if rectal mucosal prolapse, refer to dietician if food intolerance, refer to psychiatrist if pronounced stress/depression, refer to gynaecologist if cyclical pain/difficult pelvic infection

3. Treatment

   • Rarely 100% successful. Food intolerance: Exclusion diets. Constipation: increase fibre intake gradually; fibogel (ispaghula) or celevac (methylcellulose) 3-6 tablets BD with >300ml fluid. Diarrhoea: bulking agent +/- loperamide after each loose stool. Colic and bloating: Antispasmodics may help ie mebeverine. Dyspepsia: metoclopramide or antacids. Psychological therapy: emphasis 50% symptoms improve/go within 1yr. Low dose amitriptyline/psychotherapy/CBT may help.