Tenesmus is a spurious feeling of the need to evacuate the bowels, with little or no stool passed. Tenesmus may be constant or intermittent, and is usually accompanied by pain, cramping and involuntary straining efforts. It can be a temporary and transient problem related to constipation. The term rectal tenesmus is sometimes used to differentiate from vesical tenesmus, which is an overwhelming desire to empty the bladder.

Causes

There are a number of possible causes of tenesmus but the most common is inflammatory bowel disease. Causes include:

• Crohn's disease.
• Ulcerative colitis.
• Anorectal abscess.
• Infective colitis.
• Colorectal tumours, especially polyps.
• Radiation proctitis; this may follow irradiation for tumours of other sites, such as bladder tumours, cervical carcinoma and prostatic tumours.
• Irritable bowel syndrome.
• Thrombosed haemorrhoids.
• Endometriosis; can affect the rectum and cause pain and tenesmus.

Assessment

It is essential to make a thorough assessment to identify the cause of tenesmus. It is particularly important to consider serious underlying causes (e.g. malignancy, inflammatory bowel disease) when there may be associated symptoms such as weight loss and rectal bleeding.

Examination

Abdominal examination should be performed followed by both digital rectal examination and proctoscopy. There may be faecal impaction, a large polyp or very congested and inflamed mucosa.

Investigations

• If the cause of the problem is not apparent, FBC, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) may indicate an underlying inflammatory condition.
• Sigmoidoscopy and even colonoscopy may be required.
• Plain abdominal X-ray may be of value.

Management

Management will depend on the cause:

• Where the problem is constipation, simple measures such as increasing dietary fibre may help. Lactulose syrup can reduce tenesmus in the constipated elderly.¹
• Malignancy requires appropriate intervention. In advanced rectal carcinoma, radiotherapy can relieve tenesmus.²
• Endometriosis affecting the rectum may be treated medically or surgically, including laparoscopic colorectal resection.³
• A thrombosed pile requires incision and evacuation.
• In distal ulcerative colitis, topical aminosalicylates act more effectively and rapidly to induce and maintain remission than their oral preparations or topical steroids.⁴ Rarely, ulcerative proctitis is refractory to topical therapy and systemic corticosteroids, antibiotics, immunomodulators or surgery are required.
• Modern radiotherapy techniques reduce the risk of radiation proctitis and usually it responds to conservative management but intervention is required if symptoms persist. These may include topical formalin application, endoscopic argon plasma coagulation, hyperbaric oxygen therapy and surgical intervention.⁵
• Tenesmus can be a significant problem in advanced colorectal carcinoma. Morphine is usually satisfactory. Where this fails, methadone may be successful and possibly causes less constipation.⁶ Where pharmacological treatment has failed, lumbar sympathectomy gives good results which appear to persist and with few problems.⁷

Document references

1. Sanders JF; Lactulose syrup assessed in a double-blind study of elderly constipated patients. J Am Geriatr Soc. 1978 May;26(5):236-9. [abstract]
2. Midgley R, Kerr D; Colorectal cancer. Lancet. 1999 Jan 30;353(9150):391-9. [abstract]
3. Campagnacci R, Perretta S, Guerrieri M, et al; Laparoscopic colorectal resection for endometriosis. Surg Endosc. 2005 May;19(5):662-4. Epub 2005 Mar 11. [abstract]
4. Regueiro MD; Diagnosis and treatment of ulcerative proctitis. J Clin Gastroenterol. 2004 Oct;38(9):733-40. [abstract]
5. Johnston MJ, Robertson GM, Frizelle FA; Management of late complications of pelvic radiation in the rectum and anus: a review. Dis Colon Rectum. 2003 Feb;46(2):247-59. [abstract]
6. Mercadante S, Fulfaro F, Dabbene M; Methadone in treatment of tenesmus not responding to morphine escalation. Support Care Cancer. 2001 Mar;9(2):129-30. [abstract]
7. Bristow A, Foster JM; Lumbar sympathectomy in the management of rectal tenesmoid pain. Ann R Coll Surg Engl. 1988 Jan;70(1):38-9. [abstract]

Internet and further reading

• Daniel WJ; Anorectal pain, bleeding and lumps. Aust Fam Physician. 2010 Jun;39(6):376-81. [abstract]

Acknowledgements