Irritable bowel syndrome (IBS) is a common functional GI disorder characterized by abdominal pain/discomfort and altered bowel habits without structural or biochemical abnormalities. Its cause is uncertain and likely multifactorial, with psychosocial factors (stress, anxiety/depression, trauma history) often coexisting and amplifying symptoms via the brain–gut axis—contributing to variability and overlap with other functional somatic syndromes (e.g., fibromyalgia, chronic fatigue).

This review emphasizes symptom-based diagnosis using established criteria (Manning/Kruis/Rome, commonly Rome III) while avoiding extensive testing in younger patients without alarm features. Targeted evaluation is reserved for red flags, older patients, and celiac testing in non-constipating IBS. Management is individualized and multimodal: build a strong clinician–patient relationship; address diet/lifestyle (selective elimination diets/FODMAP considerations, soluble fiber like psyllium), exercise, and stress reduction; consider CBT or hypnotherapy; and tailor medications to dominant symptoms (antispasmodics/peppermint oil for pain, TCAs/SSRIs for global symptoms, PEG/secretagogues for IBS-C, loperamide for diarrhea, and alosetron for severe IBS-D with careful risk management). The authors note high placebo response rates and mixed evidence—especially for CAM/probiotics—while highlighting ongoing development of therapies targeting specific mechanisms.

Reference: Saha L. Irritable bowel syndrome: pathogenesis, diagnosis, treatment, and evidence-based medicine. World J Gastroenterol. 2014 Jun 14;20(22):6759-73. doi: 10.3748/wjg.v20.i22.6759. PMID: 24944467; PMCID: PMC4051916.

In a nationwide US survey of more than 70,000 adults, researchers compared how often and how severely lower and upper GI symptoms occur in irritable bowel syndrome with constipation (IBS-C) versus chronic idiopathic constipation (CIC). Adults (≥18 years) completed the NIH GI-PROMIS questionnaire, which uses validated scores to capture symptom frequency and intensity over the prior 7 days. The final analytic sample included 970 eligible respondents (275 IBS-C; 734 CIC). Investigators compared symptom prevalence using adjusted odds ratios and evaluated group differences in PROMIS scores, controlling for demographic differences.

Overall symptom burden was higher in IBS-C than CIC, with significantly higher adjusted global GI-PROMIS scores (251.1 vs 177.8; P<0.001). Abdominal pain stood out as a key differentiator—more common (OR 4.3) and more severe in IBS-C—while constipation severity was also modestly higher in IBS-C. Incontinence was more frequent in IBS-C (OR 2.9) but not more severe. Upper GI symptoms (dysphagia, heartburn, nausea) were similarly prevalent across groups, although heartburn severity was greater in IBS-C. The authors conclude that IBS-C generally has a more severe symptom profile than CIC, but CIC still commonly includes abdominal pain, bloating, and upper GI symptoms.

Reference: Shah ED, Almario CV, Spiegel BMR, Chey WD. Lower and Upper Gastrointestinal Symptoms Differ Between Individuals With Irritable Bowel Syndrome With Constipation or Chronic Idiopathic Constipation. J Neurogastroenterol Motil. 2018 Apr 30;24(2):299-306. doi: 10.5056/jnm17112. PMID: 29605985; PMCID: PMC5885729.

A recent article outlined a patient-centered approach to IBS-C through the case of “CS,” a 40-year-old female internist with lifelong constipation and escalating abdominal symptoms (bloating, pain, incomplete evacuation, straining) that markedly reduced quality of life. Over-the-counter measures (high fiber, water, PEG, magnesium, Metamucil) helped produce bowel movements but caused “overflow diarrhea,” urgency, and ongoing daylong discomfort. She was diagnosed with IBS-C and started on linaclotide 145 µg daily, which improved evacuation but triggered significant diarrhea and urgency. Every-other-day dosing reduced diarrhea but led to symptom relapse on off days, with persistent straining raising concern for complications.

The piece emphasizes making a confident diagnosis using a positive diagnostic strategy (Rome IV criteria + symptom burden/QOL impact + clinical confidence other diagnoses are ruled out) and subtyping with the Bristol Stool Form Scale. It reviews FDA-approved IBS-C options with different mechanisms (secretagogues: lubiprostone, linaclotide, plecanatide; retainagogue: tenapanor), noting that head-to-head comparisons are lacking—so treatment often requires trial-and-error supported by follow-up and symptom tracking across both bowel and abdominal domains. CS switched to tenapanor 50 mg twice daily and reported good overall control with more manageable diarrhea. Key takeaways include building trust, documenting all symptoms, setting expectations that abdominal relief may lag bowel response, reassessing around 8 weeks, and switching to a different mechanism of action if response is inadequate.

Reference: Kongara K. Patient-Centered Approach in IBS-C Management. Gastroenterol Hepatol (N Y). 2025 Jun;21(6):362-373. PMID: 40896757; PMCID: PMC12397800.