What are the side effects of a colon stent?

Some potential side effects and risks of colonic stents include:

- Pain - Insertion of the stent may cause some abdominal, rectal, or pelvic pain afterward. This is usually temporary.

- Bleeding - Placement of the stent can irritate the bowel lining and cause bleeding, especially if there is an underlying tumor.

- Infection - There is a risk of developing an infection after stent placement, like diverticulitis or sepsis. This may require antibiotic treatment.

- Bowel perforation - In rare cases, the stent can puncture through the bowel wall leading to peritonitis. This is a serious complication.

- Stent migration - The stent may shift position or slide out of place, obstructing the bowel. Additional procedures may be needed to reposition or replace it.

- Re-obstruction - Scar tissue can eventually grow around or through the stent, blocking the bowel again. This means repeat procedures to place another stent.

- Bowel irritation - The stent may cause persistent abdominal cramping or discomfort. Adjusting medication may help manage this.

- Bowel dysfunction - Some patients experience diarrhea, constipation, or incontinence after a colonic stent placement. 

The risks and benefits need to be carefully considered for each patient before placing a colonic stent. Close monitoring for complications is also required after the procedure. However, colonic stenting can be an effective less invasive option than surgery for some situations like palliative treatment of colon cancer.