Case Report A 53-year-old man without significant medical history presented with abdominal pain in the left lower quadrant and constipation. He got up that morning with a cramping abdominal ache that lasted over the day. He was nauseous, had vomited once, and ructus was present. There had been a small amount of hard stool and discomfort during defecation initially, but after the general practitioner had administered laxatives, he had liquid diarrhea. There was no complaint of constipation on a regular basis; this was a new finding. Tenesmus was absent. There was no bleeding or mucous discharge. He was feverish, with a temperature of 38.2°C. On examination, the abdomen was slightly distended. Auscultation showed diminished intestinal peristalsis, without borborygmi, and percussion was tympanic. Upon palpation, the abdomen was supple: there was no reflex rigidity nor guarding, and no rebound tenderness. Upon rectal examination, a hard submucosal swelling was palpated 4 cm from the anus, at 3 o’clock, in the left rectum wall. At the time, this was considered an accidental finding that was to be investigated later. 1 2 3 Fig. 1 thick arrow thin arrow  Fig. 2 arrow  Fig. 3 arrow  Fig. 4 Excision of the rectal calculus in the operating room  Fig. 5 Excision revealed a turnip-like lesion, dimensions 3.1× 2.3×1.8 cm  4 5 1 Table I Prognosis of primary GIST Risk Size (cm) Mitotic count (per 50 HPF) Very low risk <2 <5 Low risk 2–5 <5 Intermediate risk <5 6–10  5–10 <5 High risk >5 >5  >10 >Any mitotic rate  Any tumor >10 Note et al Conclusion 1 3