Hello and Welcome to Healthcare magic forum! - The pain you have described is from Hemorrhoids(piles) and nothing like bowel cancer. - Most hemorrhoids or piles can cause mild discomfort but the pain can become severe if they become thrombosed or clotted, which is the cause for the sudden shooting pain. - I would like to suggest you to observe any bleeding or streaks of blood mixed with stool or even before or after bowel movement. - Kindly visit your general physician for further evaluation. - You need to make a few diet and life style changes like drinking plenty of fluids and water, taking more fibrous foods like salads and fruits which will cause less strain on the piles and prevent more thrombosis. Reduce in take of salt which will cause fluid retention and more thrombosis of the piles. - you can take a sit s bath - sitting in about 10 cm warm (not hot) water for 15 minutes will relieve the thrombosis and pain especially after bowel movement - Homoeopathic remedy biochemic combination number 17 taken 3 times a day is helpful to relieve the pain Wishing you good health!