BACKGROUND: Rectal cancer (RC) survivors experience significant bowel function issues after treatment. We aimed to describe self-reported dietary and behavioral modifications among long-term (≥5 yr) RC survivors to manage bowel dysfunction. METHODS: RC survivors from Kaiser Permanente Northern California and Northwest regions completed surveys either via postage-paid return mail or telephone. Summary statistics on diet/behavioral modifications data were tabulated by proportion of responses. Modifications and frequency of bowel symptoms cited and were compared by ostomy status. RESULTS: A total of 575 respondents were included (overall response rate = 60.5%). Fruits and vegetables were troublesome for symptoms, but was also helpful in mitigating constipation, obstruction, and frequency, as well as improving predictability. Many respondents attributed red meat (17.7%), fried foods (13.9%), spicy foods (13.1%), carbonated beverages (8.0%), and sweets (7.6%) to increased diarrhea, gas, and urgency. Common behavioral modifications included controlling meal portions (50.6%), timing regularity (25.3%), and refraining from late night eating (13.8%). Permanent ostomy survivors were more likely to report symptoms of obstruction, while anastomosis survivors were more likely to report urgency. CONCLUSION: Multiple modifications were attempted by RC survivors to manage bowel symptoms. Identifying diet changes among RC survivors can improve symptom management and survivorship care.