Diagnostic Code 7324 · 38 CFR §4.114
Intestinal distomiasis is a chronic parasitic infection caused by trematodes (flukes) — flat parasitic worms that colonize the intestinal tract, liver, or bile ducts after the host eats undercooked freshwater fish, contaminated aquatic plants, or other infected food. The major intestinal fluke species are Fasciolopsis buski (the giant intestinal fluke), Heterophyes heterophyes, and Metagonimus yokogawai. These parasites cause inflammation of the intestinal wall, malabsorption, persistent diarrhea, abdominal pain, and over time can produce intestinal scarring or strictures. Veterans deployed to endemic regions of Southeast Asia, East Asia, the Middle East, or sub-Saharan Africa are at risk, particularly those who consumed local freshwater fish or aquatic vegetation during forward operations. Treatment with praziquantel typically clears the acute infection, but chronic residuals can persist when the disease was advanced before diagnosis or when reinfection occurred. DC 7324 captures the chronic intestinal residuals.
| Rating | Criteria |
|---|---|
| 0% | History of distomiasis with no current symptoms — the parasites have been cleared, follow-up stool studies are negative, and no chronic intestinal residuals are present. |
| 10% | Mild chronic residuals — occasional loose stools, intermittent abdominal cramping, mild dyspepsia, or other low-grade gastrointestinal symptoms controlled by outpatient management. |
| 30% | Moderate chronic residuals — recurring episodes of diarrhea, persistent abdominal pain, weight loss, malabsorption, or evidence of intestinal scarring producing functional limitation. |
Stool studies — microscopy for fluke eggs, PCR, or serology — confirm the diagnosis during active infection. For historical infections, service medical records or post-deployment medical evaluations documenting the original diagnosis and antiparasitic treatment establish the in-service event. Endoscopy or imaging showing chronic intestinal scarring documents residuals when present. A symptom diary capturing the recurrence pattern supports the rating tier. Deployment records to an endemic region close the nexus when service medical records are sparse.
The major endemic regions are Southeast Asia (Thailand, Vietnam, Cambodia, Laos), East Asia (parts of China, Korea), parts of South Asia, and pockets of sub-Saharan Africa and the Middle East. The transmission route is consumption of undercooked or raw freshwater fish, contaminated aquatic plants (watercress, water chestnuts, certain water spinach), or water containing the parasite's larval stages. Veterans deployed to these regions, particularly those who consumed local food during forward operations, have a documented exposure pathway.
Yes — treatment with praziquantel kills the adult worms but does not provide immunity. Reinfection is possible if the veteran returns to an endemic region or continues to eat contaminated food. A documented reinfection in a veteran with a prior service-connected infection can support claims for the chronic residuals and may justify increased rating during the acute reinfection period.
Both are caused by trematodes (flukes), but they affect different organ systems. Schistosomiasis is caused by Schistosoma species that migrate through the bloodstream and lodge in the urinary or hepatic vasculature, producing very different clinical pictures (urinary, liver, or chronic systemic disease). Intestinal distomiasis is caused by flukes that stay in the intestinal tract or migrate to the liver and bile ducts directly. The diagnostic codes and treatment regimens differ, and a gastroenterology or infectious disease consult distinguishes them clearly.