Effectiveness Not Established

Sweet Potato

for Constipation

Sweet potato is a root vegetable that is a source of soluble and insoluble dietary fiber. A diet with concentrated sweet-potato fiber was examined for its effect on constipation in patients with cancer.

Research Evidence Summaries

Zou, J.Y., Xu, Y., Wang, X.H., Jiang, Q., & Zhu, X.M. (2015). Improvement of constipation in leukemia patients undergoing chemotherapy using sweet potato. Cancer Nursing, 39, 181–186. 

Study Purpose

To determine whether sweet potatoes can alleviate constipation in patients with leukemia undergoing chemotherapy

Intervention Characteristics/Basic Study Process

Patients with leukemia, while receiving the first cycle of chemotherapy, were randomized to an intervention group (n = 57) or control group (n = 63). Both the groups were given routine care that included psychological intervention, abdominal massage, increased water intake (> 3000 ml per day), appropriate physical activities for condition of the patient during chemotherapy, and dietary modification (combination of course and refined grains plus fruit intake). If patients demonstrated symptoms of constipation, then laxatives or enemas were administered. The intervention group received routine care plus a diet containing sweet potato. The intervention started the day of admission and ended the day of discharge.

Sample Characteristics

  • N = 120 (57 intervention group, 63 control group)  
  • AGE = 20–60 years
  • MALES: 56% (intervention), 54% (control)  
  • KEY DISEASE CHARACTERISTICS: ALL 31%; AML 40%; mixed phenotype acute leukemia 28%


  • SITE: Single site    
  • SETTING TYPE: Outpatient    
  • LOCATION: China

Phase of Care and Clinical Applications

  • PHASE OF CARE: Active antitumor treatment

Study Design

  • Randomized trial

Measurement Instruments/Methods

  • Rome III Criteria for Functional Gastrointestinal Disorders (FGIDs) assessed constipation and defecation
  • Other parameters collected were the number of participants in which defecation occurred within 24 hours of chemotherapy ignition; time required; satisfaction of bowel movement (BM) (score 1–3); administration of laxatives


On the second day after starting the chemotherapy, the rate of constipation was significantly lower in the intervention group compared with the control group (p < 0.001). All the items in the FGIDs criteria for evaluating constipation except for “almost no loose stools without purgative use” were significantly improved in the intervention group (p < 0.01), and the number of patients with first defecation within 24 hours after chemotherapy was significantly higher in the intervention group than in the control group (p < 0.001).  The duration of defecation was significantly shortened in the intervention group after chemotherapy (p < 0.001), but the satisfaction was similar in both groups. On the fifth day, the rate of constipation was significantly lower in the intervention group, and results were similar as day two.  All the items in the FGIDs criteria for constipation except for “sensation of anorectal obstruction” and “manual assistance” were significantly improved in the intervention group.


This study demonstrated that sweet potatoes have a positive impact on prevention of constipation and defecation satisfaction in patients receiving chemotherapy for leukemia.


  • Risk of bias (no blinding)
  • Risk of bias (no appropriate attentional control condition)  
  • Risk of bias (sample characteristics)
  • This was performed in Asia, where the food composition may be different than in other cultures.

Nursing Implications

Sweet potatoes are an inexpensive vegetable that can be easily and assessable to patients undergoing treatment for leukemia in prevention of chemotherapy-induced constipation.