Hi I am Dr.kadhir, First i would like to reassure that there is very slight chance of your child have swallowed a string and it causing any obstruction, because 1 yr old child must have attained a complete pincer grasp only at this age (pincer grasp : to hold smaller objects with two fingers) . It would be difficult swallow a string ( even if done it is unlikely to cause a constipation). If your still have fear and high suspicion then it is advised to do a abdominal x ray. My advice is to treat the constipation effectively . Chronic constipation can lead to abdominal pain, nutritional deficiency, psychological stress and other serious complications also. There are quite a number of conditions which presents with constipation, starting from a small ulcer in the anal region to some serious bowel diseases but the most common one being habitual constipation . My advice is to first rule out all other serious causes, then get treated for conditions like habitual constipation. The drugs that are recommended are : Movicol (macrogol or polyethylene glycol ) is an laxative which softens the stools by increasing its water content . Its quite safe and effective only when used properly (adequate dose and method). Method of preparing the drug and number of sachets are more important. The side effects are quite rare, mainly due to dehydration , loss of electrolytes and over dose. Movicol can be used for short term and then proper fiber diet (fruits and vegetables), adequate water and lactulose can be used. Lactulose dose can be increased cautiously ( to avoid major side effects) till satisfactory respose is obtained. When child is on these drugs, he should be monitored and it is advised to get these drugs with prescription. Thank you for the consultation in health care magic