Inclusion criteria  Age >16 years old Pelvic radiotherapy completed >6 months previously Endoscopically confirmed diagnosis of radiation proctopathy on lower GI endoscopy (sigmoidoscopy or colonoscopy) as characterised by the typical endoscopic appearances of superficial friable serpiginous telangiectasia, mucosal pallor and oedema Significant rectal bleeding (>weekly passage of blood into toilet bowl +/- anaemia which is ongoing for at least 3 months) Full colonic evaluation (colonoscopy or CT colonogram) to exclude other causes for rectal bleeding Capable of providing informed consent to a participant information sheet written in English  Exclusion criteria  Age <16 years Unable to have full colonic evaluation to exclude other causes of rectal bleeding Other untreated cause for rectal bleeding Previous Purastat treatment for RP Previous Sucralfate treatment for RP