Single anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) is a modification of the biliopancreatic diversion with duodenal switch (BPD-DS) surgery. A concern with SADI-S is chronic diarrhea and hypoproteinemia. Common channel lengthening (CCL) is a surgical procedure to increase absorption in the small intestine to decrease diarrhea.The aim of this study was to assess the occurrence and treatment of hypoproteinemia and chronic diarrhea with CCL following SADI-S surgery.Private practice in the USA.Patients were included if they underwent SADI-S from September 2013 to March 2018 and following surgery underwent CCL.Average operating time for laparoscopic CCL is 56.5 ± 4.6 min. The average bowel movements for the eight patients before laparoscopic CCL were 9.1 ± 4.7 a day. After the surgery, the bowel movements were reduced to 2.6 ± 0.4 a day. This difference was found to be statistically significantly different (p = .002). The two patients experiencing hypoproteinemia improved protein levels following CCL.CCL is an effective way to treat symptomatic chronic diarrhea after SADI-S when conservative treatments have failed.