With diverticulosis, you will want to avoid foods that are high in fiber and follow a low fiber diet with a variety of nutrients. By eating fish and chicken you are accomplishing this but you will need foods with vitamins and minerals as well. Unfortunately. many fruits and veggies are high in fiber. However, canned fruits (without skins) are acceptable. You can get a list of foods for diverticulosis from Mayo Clinic online. If you are experiencing pain, you could have an infection. You can ask the doc about antibiotics. Fissures can also be painful. Sometimes they are the result of an autoimmune response. Were you checked for Crohn's Disease? Many people with Crohn's develop fissures. Also, I still would suggest being worked up for gallbladder disease.