The fatigue that outlasts the flare

Fatigue is the symptom people with inflammatory bowel disease most often say is missing from the conversation. It is also among the hardest to raise, because the word sounds like tiredness and tiredness sounds like something everybody has. A review published in the World Journal of Gastrointestinal Pathophysiology in 2025 gathered what is actually known about it, and the first useful thing it does is establish the scale.

How common it is

A meta-analysis of twenty studies gave a pooled prevalence of 47 per cent, with a confidence interval of 41 to 54 per cent. Split by disease activity, that becomes 72 per cent in active disease, with an interval of 59 to 85, and 47 per cent in remission, with an interval of 36 to 57. The review also cites figures of 86 per cent among people with active disease and 41 to 48 per cent among those whose disease is clinically quiescent. The estimates vary, and the review reports the variation rather than settling it into one number.

It does not simply follow the inflammation

The figure that matters most in that list is the remission one. Somewhere between four and five people in every ten whose disease is quiet by clinical measures are fatigued anyway. That is the finding which separates fatigue from being a straightforward symptom of active inflammation, and it is why treating the inflammation is not, on its own, reliably the answer to it.

What the review associates it with

The risk factors it names are:

• active disease and the pro-inflammatory state that goes with it, including raised TNF-alpha, IL-1 and IL-6
• nutritional deficiency and anaemia — B vitamins, iron and copper are named
• disturbed sleep
• depression and anxiety
• changes in the gut microbiota, and the gut–brain axis
• malnutrition, muscle dysfunction, sarcopenia and physical inactivity

Several of those are measurable, and some are treatable, which is the argument for raising fatigue rather than absorbing it. Anaemia in particular has its own thresholds and its own treatment pathway, and those thresholds shift depending on whether the disease is active.

How it gets measured

Fatigue is measured by questionnaire. The review lists several validated in this population: the Functional Assessment of Chronic Illness Therapy fatigue scale, the IBD Fatigue scale, the Daily Fatigue Impact Scale, the Multidimensional Fatigue Inventory, and a paediatric multidimensional scale. It is explicit that no ideal questionnaire has been recommended for assessing fatigue in inflammatory bowel disease. A score is therefore a way of tracking your own fatigue over time, rather than a number that means the same thing in every clinic.

What has been studied

The review collects results across several approaches. These are findings from individual studies of varying size and design, not a ranked list of treatments:

• controlling disease activity — conventional treatment moved a median fatigue score from 40 to 22 over three months
• upadacitinib in ulcerative colitis — 59.1 per cent reached an improvement of five points or more on the FACIT-F scale at eight weeks, against 33.8 per cent on placebo
• solution-focused therapy — 39 per cent reached a fatigue score below 35, against 18 per cent of controls
• cognitive behavioural therapy — a greater reduction in the impact of fatigue than in its severity, at six months
• mindfulness-based cognitive therapy — improvements maintained across a nine-month follow-up
• high-dose thiamine — complete improvement in 83.3 per cent in one study
• personalised exercise programmes — a significant reduction in fatigue severity
• modafinil — 60 per cent reporting at least a 50 per cent improvement from their baseline score

There is no single established treatment here and the review does not claim one. What it does establish is that fatigue in this disease is common, is not merely a consequence of active inflammation, has identifiable contributors that can be tested for, and has been the subject of real trials — which together make it a reasonable thing to put on the agenda of an appointment rather than something to explain away.