Clinical Question: Is colchicine an effective treatment for patients with chronic constipation?

Setting: Outpatient (specialty)

Study Design: Crossover trial (randomized)

Synopsis: Chronic constipation is frustrating to treat, and a cause often is not found. Colchicine has a good safety record in the treatment of gout and other diseases, but diarrhea is a prominent side effect. In this study, gastroenterologists evaluated colchicine as a treatment for idiopathic chronic constipation in a group of 16 patients.

All of the participants had experienced constipation for at least 10 years; had not responded to treatment with fiber, bisacodyl, or anthraquinone drugs; and had no identified cause for their symptoms after an extensive evaluation. All participants but one were women, and they ranged in age from 25 to 89 years.

This was a crossover trial, but the subjects received 3.4 g of psyllium orally three times daily throughout the study period. The trial consisted of a two-week baseline period, four weeks of treatment with active drug (colchicine 0.6 mg orally three times daily) or placebo, a two-week washout period and, finally, four weeks of treatment with placebo or active drug (whichever they did not receive the first time). A crossover trial increases the power of a study, making it possible to detect a statistically significant difference in a small population.

The primary outcome was the number of bowel movements per week, which improved significantly in patients receiving colchicine (9.9 bowel movements per week versus 2.7 bowel movements per week; P =.001). Conversely, the colonic transit time decreased in the colchicine group from 63.1 to 29.1 hours. The main drawback was a small increase in abdominal pain while taking colchicine, from 2 to 2.5 on a five-point symptom scale (this is of borderline clinical significance), which decreased by the fourth week of active treatment.

Bottom Line: Colchicine is an effective treatment for idiopathic chronic constipation in women. It causes a small increase in abdominal pain, but this did not stop patients from requesting to continue treatment by the end of the study. It is not clear whether the results of this small trial generalize to men. (Level of Evidence: 2b)