 The initial clinical manifestation of vascular problems in patients with SBS is early, about 25% have their first symptoms at age 20 and more than 80% of patients have had at least one complication by the age of 40.The median survival for one study of SBS patients was only 48 years.The condition was originally named for German physician Georg Sack, who described a single case in 1936, and British surgeon A.P.