Hello, Welcome to Health Care Magic. I read carefully your query and I understand your concern. Constipation can cause but not indicate infection in colon, because it can cause scratches in rectum during the stool evacuation called fissure or it can cause hemorrhoids that can be infected also during the defecation and maybe there can be a superposition of an infection. To determine it you should have symptoms. The constipation problem indicate other problem like an internal or an external obstruction of colon, it can be also a symptom of hypothyroidism, for these you should determine TSH blood level and if you have an alternately constipation with diarrhea you probably suffer from irritable bowel syndrome. To determine the cause and if you have colon infection you should go to an gastroenterologist or proctologist doctor and do examination e.g. a colonoscopy. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Kind regard, Dr .Marsida Janko