Late volume changes in retrosternal colon bypass. Esophageal obstruction by malignancy, chemical burns, or other less common entities presents a challenge for the surgeon. Either for esophageal substitution after esophageal resection or as a bypass for the obstructed esophagus, colon interposition is often the best available option. Massive colonic enlargement requiring resection of the interposed dilated colon developed recently in 2 of our patients who had a colon bypass 22 and 10 years earlier, respectively. 