Methods This is a multicentre, double blind randomized controlled trial of suture closure versus no closure in patients treated by TEM for rectal lesions. The study will include patients 18 years and older with rectal lesions within 12cm of the anal verge treated with TEM. The primary outcome is postoperative pain as measured by validated visual analogue scale (VAS). Secondary outcomes include analgesic use and early (<30 day) complications. Based on anticipated VAS scores, a sample size of 38 patients will be enrolled (power 0.80, α=0.05). Statistical analysis will be performed using student's T test for continuous data and Fischer's exact test for dichotomous variables.