Low anterior resection syndrome

This clinical trial studies if a bowel management program with a retrograde rectal enema (RRE) for the treatment of low anterior resection syndrome (LARS) in rectal cancer patients is better than medical management alone. Rectal cancer treatment can include a procedure where part of the rectum with cancer is removed and the remaining part of the rectum is reconnected to the colon, this is called a low anterior resection of the rectum. LARS is a common condition that can develop after undergoing a low anterior resection of the rectum. LARS consists of any change in how the body performs defecation, the discharge of feces from the body, after undergoing a resection procedure. Patients with LARS may experience fecal urgency, incontinence, increased frequency, constipation, feelings of incomplete bowel movement, or bowel emptying difficulties. Patients may experience individual symptoms of LARS or a combination of them. A bowel management program assists patient's with identifying a specific bowel management regimen that works best for managing symptoms of LARS. A RRE consists of inserting a catheter through the anus into the rectum. The RRE is designed to assist fecal emptying. Medical management of LARS can include the use of fiber, loperamide hydrochloride, or pelvic floor physical therapy. Fiber may help relieve constipation, feelings of incomplete bowel movement, or bowel emptying difficulties. Loperamide hydrocholoride may help lessen fecal urgency, incontinence, or increased frequency. Pelvic floor physical therapy may help restore strength in the rectum possibly helping to improve symptoms of LARS. Participating in a bowel management program with a RRE may be more effective in treating LARS than medical management alone.

This study hypothesizes that approximately 50% of rectal cancer patients can preserve their rectum using a watch-and-wait strategy if they achieve a complete or near-complete clinical response to total neoadjuvant therapy (TNT). The objective is to determine whether the complications, quality of life, and survival rates of rectal cancer patients who have achieved a complete or near-complete clinical response to TNT, followed by a watch-and-wait approach, are comparable to those of patients who undergo surgery first. Additionally, the study aims to identify potential prognostic and predictive markers for rectal cancer and examine survival rates and factors influencing responses to chemoradiotherapy (CRT) or TNT.
The study is divided into two parts:
**Part One:** Participants with cT1N1, T2-T3 N0-1 rectal cancer, MRF-, and EMVI-, with surgery as one of the possible first-line treatment options, will be randomized into two groups. The experimental group will consist of participants receiving TNT, including CRT and consolidation chemotherapy (Ch). If these participants achieve a complete or near-complete clinical response, they will be observed using a watch-and-wait strategy, which is a non-operative approach. The control group will consist of participants who undergo surgical treatment initially.
**Part Two:** All participants with rectal cancer who have received CRT or TNT will be included. Additionally, participants diagnosed with rectal cancer who are scheduled for CRT or TNT but declined to participate in Part One or do not meet the inclusion criteria will also be included.

Randomized trial to assess FMT efficacy in improving bowel function for major LARS patients. 40 subjects, blinded, randomized to FMT or probiotics. Pre-post 16S sequencing, 4-week follow-up for bowel symptoms, 8-week microbiota analysis.