FODMAP Elimination Planner Calculator

This planner builds a schedule for the three-phase Monash University low-FODMAP protocol. Monash researchers Peter Gibson and Susan Shepherd first laid out the evidence-based FODMAP approach in 2010, and the Monash University Department of Gastroenterology's low-FODMAP program has since become the reference protocol clinicians and dietitians use worldwide: a strict elimination phase (2 to 6 weeks, up to a maximum of 8), a systematic reintroduction phase where each of the six FODMAP subgroups -- excess fructose, lactose, fructans, GOS, and the two polyol types sorbitol and mannitol -- is challenged one at a time with a washout period in between, and a personalized long-term maintenance phase built from whichever groups turn out to be tolerated. Reintroduction length is driven directly by how many groups are being tested and how many challenge-and-washout days each one takes, so testing all six groups always takes proportionally longer than testing three. Expected symptom improvement is modeled from published response rates (roughly 50-80% of IBS patients report meaningful symptom relief during elimination, but that figure describes patients who actually follow the diet) scaled DIRECTLY by compliance: at 100% compliance the model reaches close to the top of that published range, capped at 85%, while a patient who reports following the diet 0% of the time is modeled as having essentially no expected benefit from it, rather than still being credited with roughly half the published response rate.

The number of FODMAP groups a patient is asked to test is capped at six -- there is no seventh group in this framework -- so long-term restriction level, which is calculated from the count of identified triggers, tops out at 100% once every tested group comes back positive and cannot go higher no matter how many additional challenges are attempted. Known Triggers Identified is meant to describe triggers already found AMONG the groups being tested, so this planner treats it as capped at the number of groups being tested when estimating safe/tolerated groups -- entering more known triggers than groups being tested describes an inconsistent scenario (you can't have found more triggers than you tested), and the calculator resolves that inconsistency rather than silently producing a zero with no explanation. This planner does not diagnose IBS, does not replace guidance from a registered dietitian trained in the low-FODMAP protocol, and does not model food combinations or portion-size sensitivity within a single FODMAP group.