What Causes Chronic Anal Fissure?
What causes chronic anal fissures? Learn how constipation, hard stools, and bowel problems lead to lasting tears and how they are treated.
Last updated:
Chronic anal fissure refers to long-term tears in the inner part of the anal canal, usually presenting with severe pain during defecation. The main feature is that the tear fails to heal within six to eight weeks.
Bowel Problems and Constipation
Constipation is one of the most common causes of chronic anal fissures. Hard and strained bowel movements damage the lining. Irregular bowel movements lead to hardened stool and increased pressure on the anal region during defecation.
The Effect of Chronic Diarrhea on Anal Fissure
Frequent episodes of diarrhea can disrupt the mucosal integrity of the anal canal due to continuous irritation, paving the way for fissure formation. Inconsistencies in stool consistency make it harder to protect the anal area.
Improper Toilet Habits
Prolonged sitting on the toilet and excessive straining are common triggers. Additionally, unnecessary straining during bowel movements keeps the tear open.
Excessive Tension in Anal Muscles
Spasms of the internal anal sphincter create high pressure in the anal canal, making healing difficult. Chronic stress and muscle tension can also lead to excessive contraction of the sphincter, contributing to the chronicity of anal fissures.
Inflammation and Infections
Localized infections and chronic inflammation can prevent anal fissures from healing over time. In particular, fungal and bacterial infections can increase tissue sensitivity in the anal region, triggering fissure formation.
Poor Diet and Nutritional Deficiencies
A lack of fiber and insufficient water intake can disrupt bowel regularity, increasing the risk of constipation. Adequate fiber and water consumption are essential for a healthy digestive system. To learn more about dietary recommendations for anal fissure patients, check out our article on how anal fissure patients should eat.
Pregnancy and Postpartum Anal Fissure
Pressure applied to the perineal area during childbirth can cause anal fissures. Postpartum rectal injuries may also make healing more difficult.
Chronic Diseases and Immune System Disorders
Crohn’s disease and inflammatory bowel diseases can increase the sensitivity of the anal mucosa, contributing to the formation of fissures.
How a chronic fissure differs from a fresh tear
A fresh fissure looks like a simple crack in the lining. When it fails to heal, the picture changes: the edges thicken, a small skin tag often forms at the outer end, and muscle fibers may become visible at the base of the tear.
These changes are more than cosmetic. Scarred edges no longer knit together on their own, which is why a chronic fissure rarely disappears with the same home measures that cure an acute one.
The spasm and blood-flow cycle
Pain makes the internal sphincter contract, and the tightened muscle squeezes the small vessels that feed the fissure. Less blood flow means slower healing, slower healing means more pain — and the cycle repeats with every bowel movement.
Effective care is aimed at breaking exactly this loop: softening the stool, relaxing the muscle and restoring circulation. The current options are summarized on the anal fissure treatment page, most of them without classical surgery.
Sources and References
- NHS - Piles (haemorrhoids)
- NIDDK - Hemorrhoids
Related articles
How Many Days Does an Anal Fissure Take to Heal?
Medical Treatment of Anal Fissures with Medication and Ointments
Resolve Your Symptoms with Confidence
With over 20 years of experience, we offer modern non-surgical treatment options. Same-day consultation is available for most patients.