After seeing this: "Patients with schizophrenia taking antipsychotics had a 308% increased colon cancer risk (adjusted OR, 4.08; 95% CI, 2.43-6.84)."
http://www.ncbi.nlm.nih.gov/pubmed/18056544
I hope you do get regular check-ups and colonoscopies. Although one little tidbit the doctors keep forgetting to tell the patients (they teach it to the nutrition students-which doesn't help the patients who don't see them) you must take probiotics following colonoscopies to avoid increased cancer risk from it.