Hello Pict,

                 sorry for your diagnosis,it comes as a hard knock.Having been through bowel and liver cancer l can say that a stoma will not stop you from riding a horse,and in some ways would be more helpful  than being without..The siting  will be within a small area  allowing for small adjustments ,so you can have a conversation with your consultant regarding positioning to suit you.As to how long you would have to be away from the saddle will vary with individuals,will depend on post op chemo if needed and how you cope,but as a guide mine was 6 three week cycles and then recovering from the pasting your body has taken,but l think its reasonable to assume you could be back into gentle hacking work 6 months to a year as your strength returns

Hope all goes well for you, 

                                            david