Chronic constipation and fecal impaction are common in older individuals but can also be found in younger patients with cognitive and psychiatric illnesses. The diagnosis of fecal impaction and, the assessment of severity are best performed clinically. Here, we present a case of a 30-year-old autistic individual where limited history was obtainable and further imaging helped to urgently diagnose a 47 x 15.6 x 12 cm stool ball, causing significant mass effect of surrounding intra-abdominal structures. Fecal disimpaction and aggressive bowel regimen prevented the pathological effects of severe fecal retention.