Abstract: To describe outcome and complications after large intestinal trocarization in equids with colic and identify factors associated with nonsurvival and clinically relevant peritonitis (CRP). Methods: 228 (198 horses, 24 ponies, and 6 donkeys and mules) equids with colic that underwent large intestinal trocarization. Methods: Medical records from 2004 through 2015 were reviewed for equids with colic that underwent large intestinal trocarization. Factors associated with nonsurvival in all (ie, surgically and medically treated) equids and with CRP in medically only treated equids were identified. Medically only treated equids with a high peritoneal fluid cell count (ie, > 10,000 cells/μL) after large intestinal trocarization were classified as having CRP if they met ≥ 2 of the following clinical criteria: anorexia, fever, lethargy, abnormal oral mucous membrane color, abnormal WBC count, or high blood fibrinogen concentration (> 5 g/L). Results: Transabdominal large intestinal trocarization was performed in 190 (83%) equids, transrectal trocarization in 17 (7%), and both procedures in 21 (9%). Of 228 equids, 167 (73%) survived to hospital discharge. None died or were euthanized because of complications from large intestinal trocarization. Nonsurvival was associated with an increasing number of trocarization procedures and diagnosis of a large intestinal strangulating lesion. A diagnosis of nephrosplenic ligament entrapment of the large colon decreased the odds of nonsurvival. Twelve of 60 (20%) equids that received medical treatment only had CRP following large intestinal trocarization. Conclusions: Large intestinal trocarization could be considered for equids with colic and large intestinal gas distension. More than one trocarization procedure was associated with an increase in nonsurvival, which should be considered for equids for which consent for surgery has been obtained.