How horrible is a 30 ft backup of stool in the colon?

Not likely scenario!: How do you define "constipation?" A medical definition is bowel infrequency (less than one bowel movement every 3-4 days). I know of no patient who died due to bowel infrequency. On the other hand, an obstructed colon that ruptures, leaks, infarcts can be life threatening if the obstruction is not relieved. By the way, your colon is about 5-6 feet long, not 30 feet--find a better source of info.