Statement of Principles concerning diverticular disease of the colon (Balance of Probabilities) (No. 52 of 2025)

This instrument is a Statement of Principles (SoP) made under subsection 196B(3) of the Veterans’ Entitlements Act 1986 (VEA). It replaces the earlier SoP concerning diverticular disease of the colon (Balance of Probabilities) (No. 16 of 2016) and takes effect on 19 May 2025. Its operative function is to specify the medical‑scientific factors that must exist (on the balance of probabilities) before a veteran or member can establish that diverticular disease of the colon, or death from that condition, is connected with the circumstances of their relevant service. The instrument thereby sets a threshold that claimants must meet to succeed in a claim under section 120B of the VEA or section 339 of the Military Rehabilitation and Compensation Act 2004 (MRCA).

Mechanically, the SoP defines the disease in question, lists fourteen categories of factors (some with sub‑conditions), and states that at least one such factor must exist and be related to relevant service. It distinguishes between clinical onset and clinical worsening, and makes clear that the clinical worsening aspects of the factors apply only where the person’s diverticular disease was suffered or contracted before or during (but did not arise out of) relevant service. Each factor is accompanied by specific time windows, dosage thresholds, or exclusion conditions (for example, non‑steroidal anti‑inflammatory medications exclude aspirin and paracetamol; immunosuppressive medications exclude inhaled or topical corticosteroids). The instrument also incorporates by reference any other SoP that covers an injury or disease to which a factor refers (section 11).

The SoP does not itself create rights or duties; rather, it operates as a binding rule of evidence for decision‑makers in the Department of Veterans’ Affairs and the Repatriation Commission, as well as for the Administrative Appeals Tribunal and courts on review. It replaces the 2016 SoP, meaning that any factor that existed only under the earlier instrument will no longer suffice unless it is also listed in the 2025 instrument. Given the balance‑of‑probabilities standard, the instrument is used where the claim does not involve operational service (which requires the reasonable‑hypothesis standard). The instrument’s practical effect is to narrow or expand the scope of claims that can succeed, depending on the new factor list.

The central legal concept is the Statement of Principles itself. Under the VEA, the Repatriation Medical Authority (RMA) determines SoPs that set out the factors that must exist to establish a causal connection between a disease and service. This SoP is made specifically on the balance of probabilities, meaning it applies to claims where the standard of proof is the civil standard (more probable than not). The instrument does not use the reasonable‑hypothesis standard, which applies to operational service claims under a different RMA determination.

Diverticular disease of the colon is defined in section 7 with some precision. It means acquired herniation of the mucosa and submucosa through the muscular layer of the colon wall. It may manifest without inflammation (diverticulosis) or with inflammation (diverticulitis). The definition expressly includes diverticular abscess, diverticular bleeding, diverticular stricture, diverticulitis complicated by bowel obstruction or fistula, and perforation of a diverticulum. The instrument cross‑references ICD‑10‑AM codes K57.2 and K57.3, but clarifies that the clinical definition in the SoP prevails over those codes for purposes of application. The concept of “death from diverticular disease of the colon” includes death from a terminal event or condition contributed to by the disease. “Terminal event” is defined in the dictionary as the proximate or ultimate cause of death, including pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function.

The instrument’s key operative concept is the list of “factors that must exist” in section 9. At least one factor must be present before the disease can be said to be connected to service. Each factor is a factual condition - such as a minimum Body Mass Index (30 or greater for five years before clinical onset or worsening), diabetes mellitus at the time of onset or worsening of diverticular bleeding, inability to undertake physical activity greater than 3 METs for five years, chronic renal failure as defined by glomerular filtration rate or dialysis, a solid organ transplant (excluding corneal transplant) before clinical worsening, or taking specified immunosuppressive medications within 30 days before onset or worsening of certain complications. Another factor involves taking non‑steroidal anti‑inflammatory drugs (excluding aspirin and paracetamol) for at least four weeks, with the last dose within seven days before onset or worsening of bleeding, perforation, abscess, or fistula. Similarly, antiplatelet medications and opioids have their own temporal windows. A substantial smoking history (10 pack‑years) within 10 years of cessation is a factor. Low dietary fibre intake (less than 30 grams per day for five consecutive years within the 10 years before onset) is a factor. Contact with a foreign object at the affected site at the time of clinical worsening is a factor. Finally, inability to obtain appropriate clinical management for the disease before clinical worsening is a factor.

The primary affected persons are veterans and members of the Forces who render relevant service as defined in the instrument. This includes those who performed eligible war service (non‑operational) or defence service (non‑hazardous) under the VEA, and those who performed peacetime service under the MRCA. Family members or dependants who claim death benefits in relation to diverticular disease of the colon are also indirectly affected, because the disease’s connection to service must be established through this SoP.

The instrument directly binds decision‑makers at the Department of Veterans’ Affairs and the Repatriation Commission. These officers must apply the SoP when assessing claims under sections 120B of the VEA or 339 of the MRCA. They cannot accept a claim based on a factor that is not listed, even if medical evidence suggests a different causal pathway. Medical advisers and expert witnesses involved in supporting or opposing claims must frame their opinions around the specific factors. For example, a medical report must address whether the claimant had a BMI of 30 or greater for at least five years before clinical onset, or whether they took a particular NSAID within the specified window.

Legal practitioners who represent veterans and members must understand the exact thresholds and time windows. The instrument imposes a compliance burden on claimants in that they must gather evidence that satisfies not only the existence of a factor but also its relationship to service. For instance, a claimant who smoked 10 pack‑years must also show that the smoking was related to their service (e.g., started or increased because of service‑related stress or as part of military culture). The instrument does not say that the factor need only exist; section 10 requires a connection to relevant service. That extra step often requires corroborating service records, medical histories, or lay evidence.

Service providers such as hospitals, general practitioners, and dietitians may be asked to produce records showing BMI over time, fibre intake, medication history, or MET capability. The stringency of definitions - especially “inability to consume an average of at least 30 grams per day of fibre in food, for at least 5 consecutive years within the 10 years before clinical onset” - places a high evidentiary bar. Many people cannot recall their fibre intake with precision, so the practical effect is that the factor will be difficult to establish without contemporaneous diet records or a pattern of institutional food supply.

The instrument also affects the Repatriation Medical Authority itself, as it must maintain consistency with other SoPs and respond to new medical‑scientific evidence. The RMA’s view that the disease can be related to service “on the sound medical‑scientific evidence available” is a claim that underpins the instrument. However, the instrument does not disclose the evidence relied upon, so practitioners cannot test that claim. The ultimate cost of the instrument is to the public purse: any claim that succeeds under these factors results in liability for compensation or medical treatment. Conversely, claimants who cannot fit their circumstances within the listed factors bear the cost of a rejected claim.

The instrument does not impose duties on individuals; instead, it creates a right for a claimant to have their claim assessed in accordance with the listed factors. If a claimant can prove, on the balance of probabilities, that at least one factor existed and that factor is related to their relevant service, then they are entitled to a finding that the disease is service‑connected. That finding opens the door to pension or other benefits under the VEA or MRCA.

The duty falls on the decision‑maker to apply the SoP correctly. They must ensure that the factor is one that is listed, that the factor meets all the temporal and quantitative requirements, and that the factor is related to service. The instrument is prescriptive: the decision‑maker cannot add new factors or accept a factor that does not precisely match the language in section 9. For example, factor 9(k) requires “having smoked at least 10 pack‑years before clinical onset or clinical worsening, and where smoking has ceased, clinical onset or clinical worsening occurred within 10 years of cessation.” If smoking ceased 11 years before clinical onset, the factor does not exist, even if the smoking was heavy and clearly service‑related. The decision‑maker’s duty is to reject such claims.

The instrument also creates a duty on the RMA to ensure that the SoP is based on sound medical‑scientific evidence, but that duty is not enforceable by individual claimants. The repeal of the 2016 SoP means that any factor that was present only under the old instrument no longer creates a right. For example, if the 2016 SoP had a factor for “constipation” or “low fibre intake” with a different threshold, that factor is now irrelevant unless it matches the 2025 version. Claimants whose circumstances fit only the old factors lose their right unless they can satisfy a new factor.

There is a subtle right in section 11: if a factor in section 9 refers to an injury or disease for which there is another SoP, then the factors of that other SoP apply. This prevents claimants from having to satisfy two sets of factors independently. For instance, factor 9(d) requires “having chronic renal failure at the time of clinical onset or clinical worsening as indicated by … a glomerular filtration rate of less than 15 mL/min/1.73 m2 for a period of at least 3 months; or undergoing chronic dialysis for renal failure.” If chronic renal failure itself is the subject of another SoP, then the claimant can rely on that SoP to establish the existence of chronic renal failure. But the instrument does not list which other SoPs are relevant.

No other rights are created; the SoP does not confer a right to treatment, to appeal, or to a specific quantum of compensation. Those matters are governed by the VEA and MRCA. The right to have the claim determined in accordance with this SoP is statutory, but the SoP itself is subordinate legislation and can be amended or replaced without compensation to affected persons.

The instrument does not itself create penalties. Penalties for false or misleading claims arise under the VEA and the Criminal Code. If a claimant knowingly makes a false statement to establish a factor (such as providing incorrect dietary records or fabricating medication use), they may face prosecution under section 137.1 of the Criminal Code (providing false or misleading information) or under the VEA’s own offence provisions. The SoP does not modify those penalties.

Enforcement of the instrument is primarily administrative. The Repatriation Commission and the Department of Veterans’ Affairs will reject claims that do not meet the factors. If a claim is incorrectly allowed, the Commission may recover overpayments under existing recovery provisions. The instrument does not set out any review rights; those are contained in the VEA and MRCA (for example, internal review, review by the Veterans’ Review Board, and review by the Administrative Appeals Tribunal).

The RMA is not directly subject to penalties for errors in the SoP. However, the VEA allows the Minister to disallow an SoP (section 196E), though that is a political check, not a legal penalty. The RMA’s determination is not subject to merits review; it can only be challenged on jurisdictional error grounds in the Federal Court (e.g., if the RMA considered an irrelevant matter or failed to take into account a relevant matter). The instrument recites that it is made on “sound medical‑scientific evidence”, but no penalty attaches if that evidence is later shown to be weak. The practical risk for the RMA is reputational, and the instrument can be superseded when new evidence emerges.

For decision‑makers who apply the instrument incorrectly, there may be internal disciplinary consequences, but no direct statutory penalty. The instrument is binding; if a decision‑maker ignores a factor or invents a new one, the claim decision is legally erroneous and likely set aside on review. That does not penalise the decision‑maker personally, but it creates administrative costs.

The SoP is a creature of the VEA, specifically subsection 196B(3). It operates within the framework of the VEA and MRCA for determining service connection. It takes effect on 19 May 2025 and repeals the 2016 SoP. The instrument explicitly states that it applies to claims to which section 120B of the VEA or section 339 of the MRCA applies. Those provisions govern the standard of proof for non‑operational service claims (balance of probabilities) and for claims under the MRCA for peacetime service. For operational service claims under the VEA, the standard is reasonable hypothesis, which is governed by separate SoPs made under subsection 196B(2). This SoP does not apply to operational service claims.

The instrument interacts with other SoPs through section 11. If a factor in section 9 refers to an injury or disease for which a different SoP has been determined under subsection 196B(3), then the factors in that other SoP apply. This cross‑referencing prevents duplication and ensures consistency. For example, factor 9(d) refers to chronic renal failure. The RMA may have a separate SoP for chronic renal failure that lists its own sub‑factors. A claimant relying on factor 9(d) does not need to prove chronic renal failure independently; they can use the other SoP. The instrument does not specify which SoPs are thereby incorporated, so practitioners must check the current list of SoPs.

The instrument also cross‑references the ICD‑10‑AM classification (Tenth Edition, effective 1 July 2017). This is a coding standard used by hospitals and the Independent Hospital Pricing Authority. The SoP references it for informational purposes only, as subsection 7(4) says “in applying this Statement of Principles the meaning of diverticular disease of the colon is that given in subsection (2)”. The ICD‑10‑AM codes are not determinative. If a medical certificate uses a different code, the clinical definition in subsection 7(2) prevails.

The instrument does not interact with state workers’ compensation laws, motor vehicle accident schemes, or private health insurance. It is solely for Commonwealth veterans’ entitlements. It does not affect tort claims or clinical guidelines. However, medical professionals should note that the definitions used (e.g., METs, fibre in food, pack‑years) are specific to this SoP and may differ from definitions used in other contexts (e.g., dietetics guidelines may define fibre differently for health promotion). The instrument’s definition of “fibre in food” is narrow, requiring plant cell walls and non‑starch polysaccharides; soluble fibre from supplements or processed foods might not count unless they meet the definition.

This instrument is the first amendment of the SoP concerning diverticular disease of the colon since the 2016 version. The source text does not disclose what changes were made between the two instruments. The instrument simply states it is made under subsection 196B(3) and repeals the Statement of Principles concerning diverticular disease of the colon (Balance of Probabilities) (No. 16 of 2016). No explanatory memorandum or statement of reasons accompanies the instrument. Accordingly, it is impossible to isolate whether factors were added, removed, or modified.

The RMA’s usual practice is to review SoPs periodically based on emerging medical evidence. The 2025 instrument likely reflects updated epidemiological studies, changes in diagnostic criteria, or new treatments (e.g., inclusion of interleukin‑6 inhibitors as immunosuppressive medications). The 2016 SoP would have had its own list of factors; comparing the two would require access to that earlier instrument. The new instrument includes factors for “taking an interleukin‑6 inhibitor” (under 9(f)(v) and 9(g)(v)), which suggests that these drugs have become more relevant in the management of diverticular disease or its complications. Similarly, the factor for “contact with a foreign object or extraneous material” (9(o)) may be new or clarified. “Inability to obtain appropriate clinical management” (9(p)) is also likely a standard factor across many SoPs.

The repeal of the 2016 SoP means that any claims relying on factors unique to that instrument will fail if decided after 19 May 2025. That is a significant amendment in effect, even if the list of factors appears similar. Without a table of changes, practitioners must assume no continuity unless a factor is identical in wording. The instrument’s commencement date is 19 May 2025, and it applies to claims to which section 120B of the VEA or section 339 of the MRCA applies. That suggests that the instrument applies to both new and pending claims, unless a specific saving provision exists. The instrument does not contain a saving provision, so it is likely fully retrospective in the sense that it applies to decisions made after the commencement date regardless of the claim date. That could be challenged as a failure to consider vested rights.

The source text does not mention any litigation history. The instrument itself is a new determination, so no court or tribunal has yet interpreted it. However, the 2016 SoP and other SoPs have been the subject of litigation in the Veterans’ Appeals Division of the AAT and in the Federal Court. Common issues include whether a factor “exists” in the sense of being present at the right time, whether the medical evidence satisfies the threshold, and whether the factor is “related to” relevant service. Courts have held that the date of clinical onset must be identified with precision.

The instrument’s definitions may generate litigation over “inability to consume an average of at least 30 grams per day of fibre in food, for at least 5 consecutive years within the 10 years before clinical onset.” The phrase “inability to consume” suggests that the claimant must show they did not consume that amount, not merely that they chose not to. But the word “inability” might be read as “failure to consume” or “incapability of consuming.” Similarly, “inability to undertake any physical activity greater than 3 METs” is defined by the cardiorespiratory effort equivalent to walking at 5 km/h. Disputes may arise about how to measure METs historically.

The “clinical worsening” factors are limited to cases where the disease was suffered or contracted before or during service but did not arise out of service. Section 10(2) excludes cases where the disease arose out of service. That may be litigated: if a claimant had diverticular disease before service that was aggravated by service, they must rely on clinical worsening factors, but if the disease arose out of service, the clinical worsening factors are not available. The distinction between “arising out of” and “aggravated by” has been disputed in other contexts.

The instrument’s reliance on “sound medical‑scientific evidence” is a jurisdictional fact. If a claimant can demonstrate that the RMA ignored contrary evidence, the SoP might be invalid for failing to consider relevant material. However, that is a challenge to the SoP itself, not a typical litigation over a claim.

No tribunal has yet considered this specific SoP. The first cases are likely to arise in 2025-2026. The AAT will be the primary forum, with appeals to the Federal Court on questions of law. The instrument’s clear language should reduce litigation compared to vaguer instruments, but strict time windows (e.g., “within 7 days before clinical onset”) will inevitably produce borderline facts. For example, if a patient took NSAIDs 8 days before onset, the factor does not exist. Claimants may try to argue that the time should be measured differently or that the “last dose” means something else.

Several traps await the unwary. First, the instrument distinguishes between clinical onset and clinical worsening. Most factors apply to both, but factors 9(b), 9(e), 9(f), 9(h), 9(i), 9(j), 9(k), 9(o), and 9(p) have specific limitations. For example, factor 9(b) only applies to “clinical onset or clinical worsening of diverticular bleeding” - if the claimant has diverticulitis without bleeding, factor 9(b) (diabetes mellitus) does not apply. Factor 9(e) (solid organ transplant) applies only “before clinical worsening” - it cannot be used to establish initial onset. Similarly, factor 9(f) (immunosuppressive medications) applies only to “clinical onset of diverticular perforation, abscess or fistula” - not to uncomplicated diverticulitis or diverticulosis. Factor 9(g) applies only to “clinical worsening” of the same conditions.

Second, the NSAID factor (9(h) and 9(i)) excludes aspirin and paracetamol. If a claimant took aspirin for heart protection, that does not count. The factor also requires continuous use for at least 4 weeks, with the last dose within 7 days before clinical onset or worsening. Intermittent use does not satisfy the continuous requirement.

Third, the antiplatelet medication factor (9(j) and 9(k)) includes aspirin (though the NSAID factor already excludes aspirin, different factors may overlap). The note gives examples: aspirin, clopidogrel, dipyridamole. The factor applies to “clinical onset” or “clinical worsening” of diverticular bleeding only (the text says “before clinical onset of diverticular bleeding” and “before clinical worsening”). The location in the instrument shows factor 9(j) does not mention a specific complication, but factor 9(j) says “before clinical onset of diverticular bleeding”. The instrument is slightly ambiguous: factor 9(j) reads “taking an antiplatelet medication that blocks platelet adhesion or aggregation before clinical onset, where the last dose of the antiplatelet medication was taken within the 7 days before clinical onset of diverticular bleeding”. So it only covers bleeding. Factor 9(k) is the same for clinical worsening.

Fourth, the opioid factor (9(l)) applies only to clinical worsening, not clinical onset. That means opioid use before the first diagnosis of diverticular disease will not help; it must be before a worsening of existing disease.

Fifth, the smoking factor (9(m)) requires 10 pack‑years and that clinical onset or worsening occurred within 10 years of cessation if the person has ceased. If the person is still smoking, there is no time limit after cessation - but they still need the 10 pack‑years. The “10 years of cessation” may trap those who quit decades ago; even if smoking caused the disease, the claim will fail if onset occurs more than 10 years after cessation.

For claimants and their representatives, compliance means gathering evidence that squarely addresses at least one listed factor and its relationship to service. The first step is to obtain the clinical definition of the disease from the medical records and confirm it matches the instrument’s definition (acquired herniation of mucosa and submucosa through the muscular layer of the colon wall, with or without inflammation). The diagnosis should be supported by colonoscopy, CT scan, or surgical findings, as the ICD‑10‑AM code alone is insufficient.

Second, identify the factor most likely to be satisfied. For many older veterans, low fibre intake, smoking, or obesity may be plausible. For low fibre (factor 9(n)), the representative should obtain evidence of dietary history for at least 5 consecutive years within the 10 years before clinical onset. That could include service mess records, dietitian assessments, or sworn affidavits describing typical meals. The word “inability to consume” suggests that the claimant must prove they did not consume 30g/day, not that they were incapable; but the better interpretation is that they did not consume that amount. The claimant should also show the low fibre intake was related to service (e.g., service food was low in fibre, or service caused post‑traumatic stress that altered diet).

Third, for smoking (factor 9(m)), the claimant must prove at least 10 pack‑years and that they quit within 10 years of clinical onset (if they quit). The relationship to service might be that smoking started or increased due to service‑related stress or that cigarettes were provided free or cheap in military environments. Military records of cigarette issues or medical records noting “tobacco use disorder” could help.

Fourth, for BMI factor (9(a)), the claimant must show a BMI of 30 or greater for at least 5 years before clinical onset or worsening. Medical records with weight and height are ideal. Relationship to service might be shown if obesity resulted from a service‑related injury that limited physical activity.

Fifth, for medication factors, the claimant must provide a clear timeline. For NSAIDs, obtain pharmacy records or medical records showing the drug prescribed and taken continuously for 4 weeks, with the last dose within 7 days before the relevant clinical event. Exclude aspirin and paracetamol. The medication use must be related to service (e.g., prescribed for a service‑caused condition).

Sixth, the representative must ensure that the clinical worsening factors are used only if the disease existed before or during service but did not arise out of service. If the disease first appeared after service, the clinical worsening factors cannot be used; only clinical onset factors are available.