Yes, some illegal drugs can be a factor in ulcerative colitis (UC):
Cocaine
Can cause ischaemic colitis, which can be life-threatening. Patients with cocaine-associated colitis have a higher mortality rate than those with ischaemic colitis.
Opioids
Chronic opioid use and misuse are associated with an increased risk of functional gastrointestinal disease (FGID) in UC patients. Chronic opioid use can also lead to narcotic bowel syndrome, which causes chronic or intermittent abdominal pain.
Just saying.........
