Irritable bowel syndrome is a common disorder of gut-brain interaction, with recurrent belly pain linked to changes in stool form or frequency. There is no structural damage, and it is diagnosed with the Rome IV criteria plus a limited workup, although symptoms can strongly affect quality of life.
Key symptoms
- Recurrent abdominal pain related to bowel movements
- Diarrhea, constipation or a mix of both
- Bloating and visible distension
- Mucus in the stool and a feeling of incomplete emptying
- Worse with stress or certain foods
What you find on exam
- Usually normal, or mild diffuse tenderness
- Weight and general look to rule out wasting
- Check for alarm signs: mass, pallor, perianal disease
- Rectal exam if constipation or bleeding
Tests
- Blood count and CRP or fecal calprotectin
- Celiac serology (tTG-IgA) if diarrhea
- Stool test for Giardia when diarrhea dominates
- Colonoscopy only for alarm features or routine screening from age 45
Treatment basics
- Explain the diagnosis and reassure; regular exercise and sleep
- Soluble fiber such as psyllium; trial of a low FODMAP diet
- Constipation: polyethylene glycol or linaclotide
- Diarrhea: loperamide; antispasmodics such as dicyclomine for pain
- Low-dose tricyclic such as amitriptyline, or cognitive behavioral therapy
Red flags
- Rectal bleeding, anemia or weight loss
- Onset after age 50, or diarrhea that wakes the patient at night
- Family history of colon cancer, IBD or celiac disease
Practice it in Making Synapses
Making Synapses cases
Related guides
Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.