Manoeuvres to "reduce" or remove the loop include pulling the endoscope backwards while twisting it. Alternatively, body position changes and abdominal support from external hand pressure can often "straighten" the endoscope to allow the scope to move forward. In a minority of patients, looping is often cited as a cause for an incomplete examination. Usage of alternative instruments leading to completion of the examination has been investigated, including use of pediatric colonoscope, push enteroscope and upper GI endoscope variants.For screening purposes, a closer visual inspection is then often performed upon withdrawal of the endoscope over the course of 20 to 25 minutes. Lawsuits over missed cancerous lesions have recently prompted some institutions to better document withdrawal time as rapid withdrawal times may be a source of potential medical legal liability. This is often a real concern in clinical settings where high caseloads could provide financial incentive to complete colonoscopies as quickly as possible. Suspicious lesions may be cauterized, treated with laser light or cut with an electric wire for purposes of biopsy or complete removal polypectomy. Medication can be injected, e.g. to control bleeding lesions. The procedure typically takes 20–30 minutes, depending on the indication and findings; with multiple polypectomies or biopsies, procedure times may be longer. As mentioned above, anatomic considerations may also affect procedure times. After the procedure, some recovery time is usually allowed to let the sedative wear off. Outpatient recovery time can take an estimated 30–60 minutes.
The main features of NUG are painful, bleeding gums and ulceration and necrosis of the interdental papilla. There may also be intra-oral halitosis, cervical lymphadenitis (swollen lymph nodes in the neck) and malaise. Treatment of the acute disease is by debridement and antibiotics, usually metronidazole. Poor oral hygiene and other predisposing factors may need to be corrected to prevent recurrence. ANUG is also known as trench mouth, as it was observed to occur in the mouths of front line soldiers during World War I.

Necrotizing ulcerative periodontitis
Necrotizing ulcerative periodontitis (NUP, or simply necrotizing periodontitis, NP) or acute necrotizing ulcerative periodontitis (ANUP) is where the infection leads to attachment loss (destruction of the ligaments anchoring teeth in their sockets), but involves only the gingiva, periodontal ligament and alveolar ligament. Usually this spectrum of diseases result in loss of attachment, and therefore many ANUG diagnoses may be technically termed NUP, although ANUG is the term in most common use. NUP may be an extension of NUG into the periodontal ligaments, although this is not completely proven. In the meantime, NUG and NUP are classified together under the term necrotizing periodontal diseases. Necrotizing stomatitis
Progression of NUP into tissue beyond the mucogingival junction characterizes necrotizing stomatitis, which has many features in similar with cancrum oris. Cancrum oris
Cancrum oris (also termed noma) is a necrotizing and destructive infection of the mouth and face, and therefore not strictly speaking a periodontal disease. In modern times, this condition usually occurs in malnourished children in developing countries. It may be disfiguring and is frequently fatal.