Passing stool should be neither a painful, nor a difficult process. With a healthy bowel movement, the passage of stool will require minimal to moderate effort. Straining to defecate, painful intestinal cramps and pain while defecating are abnormal and can be an indication of various disorders affecting the large bowel, rectum or anus. It may also emanate from the other abdominal and pelvic organs, as well as the pelvic and perineal structures or buttocks, groin area, upper thighs or even the lower back. The entire defecation process is outlined in these articles on defecation and the defecation reflex.

Painful bowel movements should be investigated as there are a host of causes, some of which are related to serious conditions, where pain during defecation is the only symptom initially. Monitoring other signs and symptoms related to defecation may also help with  diagnosis especially if there is a lack of clinical features indicating a possible cause. Patients should take note of :

Causes of Painful Bowel Movements

Anorectal Trauma

Injury to the anus and/or rectum may occur for a number of reasons and will lead to pain during defecation. Anal intercourse, vigorous cleaning/wiping of the anal area, accidental injuries to the anus, enemas and even the passage of very hard, dry or large feces in constipation may injure the lining of the rectum and anus. Foreign bodies inserted into the anus or rectum may also cause trauma and can contribute to severe pain if it is lodged in the area.

Abscess and Fistula

An abscess within the abdominopelvic cavity, in the organs or around the anus may also be a cause of painful defecation. This may include an intra-abdominal abscess, pelvic abscess, ovarian abscess (women), prostate abscess (men) and perianal abscess.

A fistula is an abnormal passageway that forms between two hollow organs. It may be a complication of an abscess but can occur for other reasons. Certain types of fistulas that affect the abdominopelvic structures may lead to painful bowel movements. This includes an anorectal, rectovaginal (rectum to vagina), vesicorectal (bladder to rectum), and urethrorectal (urethra to rectum) fistulas.

Infection and Inflammation

Inflammation of the lower part of the gut and pelvic organs may also contribute to pain during defecation. It may occur for a number of reasons, including mechanical and chemical trauma, autoimmune factors and infections. This includes the rectum (procititis), colon (colitis), prostate (prostatitis), bladder (cystitis), and small intestine (enteritis), pelvic inflammatory disease, vaginitis (vagina) and endometriosis in women. Although the prostate, vagina, uterus and bladder are not involved in the process of defecation, the increased perineal pressure associated with defecation may irritate the already inflamed organ. Bowel conditions like inflammatory bowel disease and diverticulitis often present with painful bowel movements.

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Infectious causes may be due to a host of pathogens with various methods of transmission. Sexually transmitted infections should always be considered when acute infections are seen in sexually active patients. Chlamydia, gonorrhea, syphilis and genital herpes especially may affect the anal region.

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Altered Bowel Habit

Constipation and diarrhea may be seen with a number of diseases. The frequency of bowel movements in diarrhea and difficulty in constipation can often irritate the lining of the rectum and anus if it was not involved as part of the primary condition. This can contribute to painful defecation. Furthermore, the dry, hard feces, straining, hemorrhoids and fecal impaction seen in conjunction with constipation may further contribute to painful bowel movements.

Anal Fissures, Warts and Hemorrhoids

Anal fissures are tears in the lining of the anus. It may be minute and extend to the skin around the anus. It is frequently seen with constipation or diarrhea but may also arise with trauma to the anus, allergic reactions, STDs and other infectious and inflammatory disorders. Pain occurs with the passage of stool irritating the underlying tissue that is exposed to the environment.

Anal warts are often associated with the human papillomavirus (HPV) and is commonly transmitted sexually. It is more likely to cause pain with defecation if it is large, inflamed and excoriated.

Hemorrhoids are swollen and inflamed blood vessels in the lower rectum (internal hemorrhoids) and anus (external hemorrhoids). It is seen with constipation and chronic diarrhea, in pregnancy and anal trauma and occurs more frequently in obese people. Itching, bleeding and pain during and after defecation are common symptoms.

Skin Diseases

A number of skin disease may involve the perianal area, anus or even extend slightly into the anal canal. This can vary from conditions like psoriasis and eczema (read more on the types of eczema) to infectious conditions like cellulitis, necrotizing fasciitis, and fungal infections of the skin.

Tumors and Growths

Benign growths like polyps in the colon may present with painful defecation if it is large and ulcerated although there may be no other symptoms. Malignant tumors like colorectal carcinoma may also be responsible for painful bowel movements, along with rectal bleeding, weight loss and altered bowel habits. Large tumors involving the other organs of the pelvic cavity may also cause pain upon defecation, especially of the uterus, cervix and vagina in women (uterine cancer, cervical cancer and vaginal cancer), prostate in men (prostate cancer) and bladder in both sexes (bladder cancer).

Other Causes

  • Lumbosacral back pain (lower back pain)
  • Coccydynia (tailbone pain)
  • Lumbar neuritis
  • Abdominopelvic hernias
  • Rectal strictures
  • Rectal prolapse
  • Ectopic pregnancy
  • Polycystic ovarian syndrome (PCOS)
  • Sexual abuse

Article reviewed by Dr. Greg. Last updated on April 5, 2011