Methylcellulose is a dietary fibre supplement used to treat constipation, excessive appetite and diverticulitis. Two to five tablets are taken three times a day with water before meals. It is safe in pregnancy and breastfeeding, but not recommended in children. Ensure an adequate fluid intake while using methylcellulose, but do not use it if suffering from a bowel blockage. Loose bulky motions are the only side effect. The absorption of a wide range of medications may be affected when methylcellulose is used, although it is totally inactive in body, and merely acts to add bulk to faeces.