Living with Low Anterior Resection Syndrome

Low anterior resection syndrome is a series of ongoing issues individuals may experience of after undergoing treatment and surgery for rectal cancer.  To best understand why the symptoms of Low Anterior Resection Syndrome (LARS) occur, we should first understand what is happening in a Low Anterior Resection (LAR) procedure:

 

What is a Low Anterior Resection?

LAR involves surgical removal of a majority portion of, or the entire rectum and the sigmoid colon, while hooking up the remaining rectum with the end of the colon.  This hookup is referred to as an "Anastomosis" and achieved during the LAR procedure by the colon and rectum being sewn or stapled back together.  The goal of a LAR procedure is curative removal of a malignant rectal tumor

Note in images 1 and 2, how the initial anatomy can be loosely described as a 'question mark' (?) and how the potential future anatomy resembles a 'seven' (7).  This difference in anatomy is important when considering the issues involved with LARS.
 

Image 1.  Anatomy of the Colon & Rectum Prior to Low Anterior Resection

Image 1 - The anatomy of the colon and rectum - highlighting a possible location a Low Anterior Resection procedure.

Image 2.  Anatomy of the Colon & Rectum After Low Anterior Resection

Image 2 - Possible anatomy of the colon and rectum after Low Anterior Resection.

Image 2 - Possible anatomy of the colon and rectum after Low Anterior Resection.

 

Loop Ileostomy

Following the LAR procedure, most rectal cancer patients undergo a Loop Ileostomy or Diverting Ileostomy.  This ileostomy is usually temporary and diverts stool from the colon and resected rectum to allow for healing of the anastomosis, and instead the stool comes out of a stoma on the right side of the abdomen and into an ileostomy bag.  [This is not to be confused with a colostomy, which is permanent and diverts into a stoma from the colon]  

After a period of 4-6 months, the ileostomy is reversed, allowing stool to continue passing down into the colon and very quickly triggering the symptoms of LARS.

A key suspected factor causing LARS is this 4-6 month period of healing in the colon as the inactivity during this time can cause issues with stool motility among other factors, like colon flora.

Image 3.  Anatomy of the Small Intestines with Loop Ileostomy Diverting from the Colon & Rectum after Low Anterior Resection 

Image 3 - Loop Ileostomy is a temporary diversion of stool out of a stoma on the right side of your abdomen and into a ileostomy bag.  

Image 3 - Loop Ileostomy is a temporary diversion of stool out of a stoma on the right side of your abdomen and into a ileostomy bag.  

 

If your treatment requires a Low Anterior Resection, you may be at risk for LARS.  What symptoms should you expect after surgery?

LARS symptoms are unique for everyone, and the speed in which symptoms subside after are dependent upon your unique situation.  The most common noted symptoms of LARS include:

  • Extremely increased frequency of bowel movements
  • Increased and often immediate urgency of stools
  • Clustering of stools - high number of bowel movements in a short period of time (hours)
  • Fecal incontinence or reduced control over bowel movements
  • Extreme sensitivity to foods high in insoluble fibers
  • Constipation for a period of days, followed by clustering days later
  • Increased gas, sometimes uncontrollable
  • Rectal pain (near site of anastomosis and/or radiation)
  • Rectal tissue swelling