Disorders of swallowing, chewing, sucking, and absorption are called dysphagia. Problems with sucking include difficulties in eating, chewing, absorbing, and swallowing. For example, a child may refuse to eat: if it is solid food — they do not want to bite; if it is pureed food — they do not put it in their mouth; if it is liquid — they cannot swallow.
Or an infant may have difficulty sucking breast milk — they cannot fully latch onto the breast, keep their lips open, which causes problems with sucking. In such cases, the child may have an impaired sucking reflex.