Irritable Bowel Syndrome (IBS)

IBS management at Shree Hospitals is structured around five sequential steps: establishing a confident positive diagnosis using Rome IV criteria, performing targeted investigations to exclude serious organic pathology, classifying the IBS subtype to guide specific therapy, implementing evidence-based dietary modification with specialist dietitian support, and deploying pharmacological and gut-brain interventions that are matched to symptom pattern, severity, and the individual patient's response. IBS is one of the most commonly undertreated and incorrectly managed GI conditions in clinical practice - not because treatment is unavailable, but because the condition requires a structured multi-modal approach rather than a single empirical prescription.

Step 1 - Positive Diagnosis Using Rome IV Criteria

IBS is not a diagnosis of exclusion - it is a positive clinical diagnosis made using internationally validated Rome IV criteria when the characteristic symptom pattern is present. Rome IV defines IBS as recurrent abdominal pain occurring on average at least one day per week for the previous three months, associated with two or more of the following: relationship to defaecation (pain that improves or worsens with a bowel movement), change in stool frequency (more frequent or less frequent bowel movements during pain episodes), or change in stool form (looser, harder, or urgency-associated stools during pain episodes). At Shree Hospitals, a structured history maps the full symptom profile using Rome IV, records symptom duration, identifies aggravating and relieving factors, maps the relationship between meals, stress, and symptoms, and applies the Bristol Stool Chart to characterise stool form systematically.

Step 2 - Ruling Out Organic Disease: Targeted Investigations

Once Rome IV criteria are met and alarm features are absent, targeted investigations are performed to exclude the organic conditions that can mimic IBS - not a comprehensive "IBS workup" that over-investigates, but a focused screen based on the clinical picture. Standard investigations include: full blood count and CRP (elevated in IBD - inflammatory bowel disease; normal in IBS), tissue transglutaminase IgA with total serum IgA (coeliac disease serology - coeliac mimics IBS-D in up to 5% of cases), stool calprotectin (an intestinal inflammatory marker significantly elevated in Crohn's disease and ulcerative colitis but normal in IBS), and thyroid function tests. Colonoscopy is not routinely required for IBS below age 45 without alarm features - it should not be performed reflexively in every IBS patient, as it adds procedural risk, cost, and anxiety without diagnostic yield when calprotectin is normal and alarm features are absent.

Step 3 - IBS Subtype Classification: Tailoring Therapy to the Dominant Pattern

Rome IV classifies IBS into four subtypes based on predominant stool pattern: IBS-D (diarrhoea-predominant: loose or watery stools in >25% of bowel movements), IBS-C (constipation-predominant: hard or lumpy stools in >25% of bowel movements), IBS-M (mixed: both loose and hard stools on different days), and IBS-U (unclassified: does not fit the above three patterns). Subtype classification drives pharmacological prescribing - antidiarrhoeals and specific gut serotonin modulators for IBS-D; secretagogues and osmotic laxatives for IBS-C; antispasmodics and fibre for all subtypes. Patients frequently shift between subtypes over time, particularly after dietary changes or intercurrent gastrointestinal infection.

Step 4 - Low-FODMAP Diet and Structured Dietary Modification

The low-FODMAP diet - restricting fermentable oligosaccharides, disaccharides, monosaccharides, and polyols - is the most evidence-based dietary intervention for IBS globally, producing clinically meaningful symptom reduction in 50–70% of IBS patients who complete a structured supervised protocol. FODMAPs are poorly absorbed short-chain carbohydrates that are rapidly fermented by the colonic microbiome, producing gas, water, and the bloating, cramping, and altered stool pattern that characterise IBS. At Shree Hospitals, every IBS patient is assessed by our specialist GI dietitian, who adapts the low-FODMAP protocol to Indian dietary patterns - identifying high-FODMAP Indian foods (wheat products, onion, garlic, certain dal varieties, lactose-containing dairy, mango, apple, watermelon) and providing low-FODMAP substitutes compatible with Indian cooking and cultural preferences.

Step 5 - Pharmacological and Gut-Brain Axis Treatment

IBS pharmacotherapy is subtype-specific and severity-stratified. Antispasmodics - mebeverine, hyoscine butylbromide, peppermint oil capsules - reduce post-meal visceral cramping in both IBS-D and IBS-C. For IBS-D refractory to dietary measures, rifaximin (non-absorbable antibiotic) addresses small intestinal bacterial overgrowth (SIBO), which overlaps with IBS in up to 30% of patients and independently drives bloating and loose stool. Loperamide reduces stool frequency and urgency in IBS-D. For IBS-C, osmotic laxatives (polyethylene glycol, lactulose) and secretagogues (linaclotide) improve stool consistency and frequency. The gut-brain axis - the bidirectional neural communication network between the enteric and central nervous systems - is dysregulated in IBS, producing visceral hypersensitivity (heightened pain perception from normal gut events) that psychological intervention directly addresses. Low-dose tricyclic antidepressants (amitriptyline 10–25mg) are neuromodulators - not antidepressants - at these doses, reducing central visceral pain perception. Gut-directed cognitive behavioural therapy and gut-directed hypnotherapy have NICE-level evidence for IBS and are offered at Shree Hospitals for patients with significant anxiety, catastrophising, or stress-triggered symptom patterns.