Drug-associated hemorrhagic colitis are divided into antibiotic associated hemorrhagic colitis (AAHC) and other drug associated hemorrhagic colitis. AAHC are mainly caused by oral usage of Ampicillin and its derivatives (85%). Initially AAHC are believed to be caused by Klebsiella oxytoca overgrowth. However, these organisum has no exotoxin like Clostridium difficile and pathogenesis of AAHC are still unresolved. Typical AAHC are diagnosed by colonoscopy with diffuse hemorrhage and edema mainly found in descending colon and transverse colon. NSAIDs are also the cause of hemorrhagic colitis like AAHC. Mephenamic acid are famous for this complication. Diarrhea is one of the main complication of oral 5-fluorouracil administration and even causes hemorrhagic colitis. Its histology are characteristic in gland atrophy. Gold colitis are reported 36 cases in rheumatoid arthritis patients. Exact mechanism of bleeding are not understood. NSAIDs may cause collagenous colitis and or lymphocytic colitis in RA patients. Other rare hemorrhagic colitis are associated with azathioprine, methyl dopa, interferon alfa etc. NSAIDs and anticoagulants are well known drugs for complication of GI bleeding making hemorrhagic enteritis.