Can a perforated colon heal itself with antibodies?

No: Anti-bodies do not seal tissue they are part of the immune system. Although small: perforations can become walled off spontaneously larger perforations require surgical intervention. The latter is almost always the case, unless the small perforation occurred during colonoscopy or is due to small diverticular disease

Sometimes: Small microperforations of the colon can heal with bowel rest and ANTIBIOTICS, but you need to be prepared for operation in case that doesn't work.