By computer search of the literature, we found few cases of hydronephrosis due to fecal impaction. Because such a complication is extremely rare, we describe an 81-year-old woman with dementia, gallstones, arterial hypertension, and diverticulosis of the sigma who was hospitalized for severe constipation, fecaloma, and bilateral hydronephrosis. Through simultaneous lavage by two rectal tubes and manual disimpaction of fecaloma, bilateral hydronephrosis was resolved. We also briefly review the appropriate literature.