We report a case of chronic intestinal schistosomiasis presenting in a previously asymptomatic 34-year-old woman from Saudi Arabia with large B cell lymphoma. The patient presented with abdominal pain, constipation, recurrent rectal bleeding, and persistent mild eosinophilia during chemotherapy. Stools were repeatedly negative for parasite ova, but duodenal and colonic biopsies demonstrated Schistosoma eggs and eosinophilic granulomatous inflammation. Immunosuppressed patients with schistosomiasis may have diminished egg excretion. Diagnosis requires a high index of suspicion since stool test results may be negative and intestinal biopsies may be needed to make the diagnosis.