Celevac 500mg Tablets This medicine is a bulking agent which is used to maintain the consistency of stools. It can help relieve symptoms of both diarrhoea & constipation & may be useful for people who have had part of their bowel removed. t can also be used to control diarrhoea, constipation, & spasmodic pain caused by conditions such as diverticular disease or ulcerative colitis. Because it is a bulking agent it can produce a feeling of fullness which can help control appetite as part of a treatment plan for obesity. This medicine works by absorbing water in the bowel & swelling. The increased bulk in the bowel helps regulate bowel movement & improve stool consistency. This medicine is available as tablets that are taken by mouth. It is best to chew the tablets before swallowing them. Do not take this medicine just before going to bed. Speak to your doctor if your symptoms do not improve or if they get worse during treatment with this medicine.