Can hemorrhoidectomy and/or fistulotomy cause permanent loss of sensation or altered feeling (guarding) in the inner rectum?

Hemorrhoidectomy and Fistulotomy: Risk of Permanent Rectal Sensation Loss

Hemorrhoidectomy and fistulotomy can cause permanent alterations in rectal sensation and function, though complete permanent sensation loss is rare with standard techniques. The risk depends on the specific procedure, surgical technique, and extent of sphincter involvement.

Hemorrhoidectomy-Related Sensory Changes

Conventional Hemorrhoidectomy

Conventional hemorrhoidectomy (Milligan-Morgan technique) carries documented risks of altered sensation and function:

• Sphincter injury occurs in up to 12% of patients, documented by ultrasonography and anal manometry 1
• Incontinence rates range from 2-12% after conventional hemorrhoidectomy 1
• The internal sphincter is almost universally injured in patients who develop post-operative incontinence, with a characteristic pattern of distal high-pressure zone injury that reverses the normal resting pressure gradient in 89% of affected patients 2
• Reduced resting pressure at the high-pressure zone has been documented in symptomatic patients 3

The mechanism involves excessive retraction and extensive dilation of the anal canal during surgery, which damages sphincter structures 1. However, these changes primarily affect motor function and continence rather than causing complete sensory loss.

Stapled Hemorrhoidectomy

Stapled hemorrhoidectomy presents a different risk profile for sensory changes:

• Rectal distensibility and volume thresholds for sensations significantly decrease after stapled hemorrhoidopexy 4
• 41% of patients develop increased stool frequency and/or fecal urgency associated with altered rectal distensibility 4
• One trial reported persistent pain and fecal urgency lasting up to 15 months in 5 of 22 patients 1
• Fragmentation of the internal anal sphincter occurred in 14% of patients using standard technique 1

Critical caveat: The stapled technique can inadvertently include full-thickness rectal wall (including smooth muscle) rather than just mucosa and submucosa, which may explain altered sensation 1.

Fistulotomy-Related Sensory Changes

Fistulotomy carries similar but distinct risks:

• Internal sphincter injury is virtually universal in patients developing post-operative incontinence after fistulotomy 2
• When combined with primary sphincteroplasty, the overall success rate is 93.2%, with postoperative continence worsening in only 12.4% (mainly post-defecation soiling) 5
• Anorectal manometry parameters typically remain unchanged when proper sphincter-sparing techniques are used 5

Nature of Sensory Changes

Important distinction: These procedures typically cause functional changes rather than complete permanent sensation loss:

• The anal cushions normally contribute 15-20% of resting anal pressure and serve as a conformable plug for complete anal canal closure 1
• Surgical disruption affects this mechanical function and pressure sensation more than eliminating sensation entirely
• Complete anorectal sensory loss only occurs with radical procedures like total anorectal reconstruction, where patients lose the ability to perceive rectal distension as a desire to defecate 6

Clinical Implications and Risk Mitigation

To minimize permanent sensory and functional changes:

• Avoid excessive retraction and extensive anal canal dilation during hemorrhoidectomy 1
• For stapled hemorrhoidectomy, ensure excision includes only mucosa and submucosa, not full-thickness rectal wall 1
• Consider sphincter-sparing approaches for fistulas, including fistulotomy with primary sphincteroplasty 5
• Recognize that lateral internal sphincterotomy as an adjunct actually increases incontinence risk and should be avoided 1

Key takeaway: While altered sensation and function can occur, true permanent complete sensation loss of the inner rectum is not a typical complication of standard hemorrhoidectomy or fistulotomy. The more common issues are reduced pressure sensation, altered distensibility, and functional changes affecting continence—particularly when surgical technique is suboptimal or when extensive sphincter involvement is necessary.